Chevy 350 stumbles under load

sure, 20 at idle. but the second to hit the throttle and load up the engine the vacuum advance drops off (back to 8), which makes it bog. You need more mechanical timing. Vacuum advance goes away under load. I run 15 to 20 initial then run the vacuum advance connected to the manifold for a total of 30 to 35 at idle.Some customers may comment on a 1-2 shift shudder at light to moderate acceleration. Typically, the throttle plate angle parameter is 12-20% at time of condition with vehicle speed of approximately 24-40 km/h (15-25 mph). The customer may describe the condition as slip or delayed shift into second. Correction.At lower throttle settings, the intake manifold has significant vacuum as the engine keeps pumping air and the throttle plate is at least partially closed. The pressure inside the manifold that feeds into the intake valve is less than atmospheric pressure. This is a less dense charge, and ignites easily.Dec 22, 2017 · Timing wire unplugged 0 degree.... Tps less than 4 @ idle....4 with increased idle I believe. Chevy Mechanic: Roy Belding. tps should be .5 to .75 volts at idle and increase according to pedal up to 4.8. timing should be set to 6 to 8 degrees. you have retarded timing at this point. Roy. the o2 sensor is a used for fuel trim, if you continue to run the truck with a lean condition, your likely to burn a valve, but a vacuum leak can cause a lean condition, and with the rpm acting that way, i would really check for a hissing sound on all the vac hoses, intake manifold, power booster, ect.. it won't hurt to check the fuel pressure, …If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. Jul 18, 2011. 16. MN. I have an off idle stumble with my Edelbrock carb and cant seem to cure it. I am using an Innovate LM2 to help tune, everything is fine @ idle, under load, and WOT. It seems like when the carb goes from the idle system to the priamary main system it goes lean for a split second ( it shows on the LM2) and I get a hesitation ...At lower throttle settings, the intake manifold has significant vacuum as the engine keeps pumping air and the throttle plate is at least partially closed. The pressure inside the manifold that feeds into the intake valve is less than atmospheric pressure. This is a less dense charge, and ignites easily. Jul 03, 2011 · As it gets under load in higher gears it starts to sputter bad, especially in 3rd gear right before shifting into 4th (700r4 trans) Engine is a 10.5:1 compression (flat top pistons) 350 Chevy that's freshly rebuilt and is run on 93 oct gas, ignition timing is set at 10-12° idle, 700 rpm, and 34-36° at 3500 rpm. If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. I am having a misfire under load problem. The motor only has about 20 miles on it. I know the following about the motor / set up: 383 stroker Scat crank Scat rods Hyper pistons Approx. 10.8 - 1 CR Pro Comp Aluminum heads 190 cc Pro Products performer style intake Demon 750 vac. sec. carb Roller rockers Approx. 500 lift roller cam Hei dizzy1.) with the air cleaner off, and engine off, actuate the throttle and see if the accel pump is squirting. 2.) ensuring the choke pull off isnt holding them, tap the secondary butterflys with your finger to open them. Now, unless you've played with QJets, like Mike up there who runs a dyno for Ford! , then you'll have no way of "feeling" it.I have a 1999 GMC Yukon with a Vortec engine and 130,000 miles. My issue first showed up at 35,000 miles and has shown up from time to time since then, getting progressively worse. Sometimes, the Yukon would start to misfire when towing and occasionally when just going up a hill around 70 mph. The truck would start to shudder and shake and even ...From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Nov 18, 2011 · wolfen1086. Moderator, Automotive Team. Joined Oct 4, 2007. 13,890 Posts. #3 · Nov 19, 2011. the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from. K. Start the engine, and warm to normal operating temperature. Shut off the engine. Remove the air cleaner. The choke butterfly should be fully open, as the engine is warm. Observe the pump jet in the carburetor, and with your hand, work the carburetor throttle to the wide-open position. You should observe a healthy squirt of fuel from the pump jet.6,308. MN. The TPS on a TBI engine is not adjustable. You need to have a scanner of some sort to see the voltage and it should go from .5 to 4.5 at WOT. The voltage should look smooth with no voltage flat spots. One thing I do know that TBI engines do is hesitate from the EGR opening too soon.Turns out there are two very common and easily correctable problems with tbi motors. First, the fuel pumps are extremely picky and prone to fail if run out of fuel. Sometimes it is no big thing, sometimes pressure/volume problems arise. Easy to replace, any junkyard with chevy/gmc trucks has a dozen of them.If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. At lower throttle settings, the intake manifold has significant vacuum as the engine keeps pumping air and the throttle plate is at least partially closed. The pressure inside the manifold that feeds into the intake valve is less than atmospheric pressure. This is a less dense charge, and ignites easily.Aug 21, 2019 · It will start normally and idle fine (with a barely noticeable misfire). It behaves pretty well until it starts to warm up. After warming, the engine starts missing significantly when I give it a little throttle (neutral or in gear). If I keep a light throttle in neutral the miss will get worse until it barely keeps going. granite state dog recovery phone number Usuallly weak spark cause a misfire under a load,the compression increases when you open the throttle and can snuff out a weak spark --the cap and rotor can cause this even if they look perfect,but spark plug wires that are cracked,burnt from lying on an exhaust manifold or header will do the same,so can plugs that are fouled,or a weak ignition coil or pickup coil,sometimes the ignition module ...90Brougham350 Registered 94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold) Joined Jan 12, 2005 3,710 Posts #3 · Feb 26, 2006 500,000 miles? You need a new timing chain, and your timing is more than likely off, this is usually what causes backfires, but the stretched timing chain is more than likely making things worse.Apr 23, 2010 · You should be getting at least 5 psi under load. Make sure plug wires are "snapped" onto plugs tight. If not tight, give the ends a squeeze with pliers until you can feel them snap onto plugs. Do same at distributor end. Check fuel level in float bowl. Adjust needle and seat until fuel JUST drips out of site plug hole while running. Nov 18, 2011 · wolfen1086. Moderator, Automotive Team. Joined Oct 4, 2007. 13,890 Posts. #3 · Nov 19, 2011. the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from. K. 5,421 Posts. #7 · Dec 7, 2003. Well this is probably not it, but just another suggestion as a "last resort," Clint's 98 350 kept dying and it was because of a bad battery connection. It would be fine in park but as soon as you put it into any gear, it would die. Found out that the battery was not getting a good enough connection.Dec 26, 2009 · I have a 1994 Chevy 350 , upon attempting to accelerate there is a lot of hesitation or sputtering from the motor. Thought it was a dirty carb or water in the gas but thats not it. Was told by a frend that it could be a bad distributor cap and rotor , any comments on this diagnosis ? The truck has 120 K miles on it Answered in 2 minutes by: Aug 21, 2019 · It will start normally and idle fine (with a barely noticeable misfire). It behaves pretty well until it starts to warm up. After warming, the engine starts missing significantly when I give it a little throttle (neutral or in gear). If I keep a light throttle in neutral the miss will get worse until it barely keeps going. Feb 07, 2009 · I have a 79 chevy 3/4 ton pickup with a fresh 350 bored 40 over it has an edelbrock rpm air gap intake, edelbrock 600 cfm carb, headers, accel coil, and cranes power max cam with an advertised duratio … The car/engine (specs are at the end of this post) bogs down under load. Specifically, when I give it gas, the engine initially responds normally, but then bogs down/stumbles. Then, I give it a bit more gas. Again, the engine initially responds normally, but then bogs down. The engine runs fine idling and when I give it gas with the trans in ...Oct 07, 2013 · Thank you for the help! Specs: 1978 block 350 bored .060 over. holley alum heads 2.02/1.60 valves. 9-9.5:1 compression. Holley 670 cfm street avenger carb w/ Vac Sec. and elec. choke 65 pri and 68 sec using 'middle' spring. lunati .477-.507 lift 225-235*@.050 duration 112* lobe separtion cam. I have a 1999 GMC Yukon with a Vortec engine and 130,000 miles. My issue first showed up at 35,000 miles and has shown up from time to time since then, getting progressively worse. Sometimes, the Yukon would start to misfire when towing and occasionally when just going up a hill around 70 mph. The truck would start to shudder and shake and even ...Mar 21, 2009 · It has a period 350 with single hump heads, HEI distributor, MSD Ignition, headers,very mild or stock cam, and a carter AFB comp carb. TH350 tranny The car starts real good, idles real good. But it feels really low on power and has a miss under load. It revs up fairly clean when sitting still, and its not as bad in first. houses to rent stoke on trent These misfires do often come under load from the engine, like when you are accelerating hard. The most common situation to notice misfires is on high gears, low RPM, and the accelerator to the floor. Rough acceleration is a typical sign that your engine is misfiring. 2. Rough IdleSep 21, 2016 · Other observations. 1. Problem is only under load. When in the water in neutral throttling in that rpm range is smooth and trouble free. 2. fuel tank air vent is clear. 3. vital signs at idle: engine runs at 168f, fuel pressure steady at 42.8, water pressure at 3.7, oil pressure 49.1. Had a similar thing happen and it ended up being a hole in the water jacket. Was a small leak in the top of the cylinder. Would run fine off the hose in the back yard but under load would crumble. Ended up replacing the engine for a newer 1. Apparently happens a fair bit at the cylinder closest to the water.I have a 79 chevy 3/4 ton pickup with a fresh 350 bored 40 over it has an edelbrock rpm air gap intake, edelbrock 600 cfm carb, headers, accel coil, and cranes power max cam with an advertised duratio …I have a 97 Suburban 5.7, 2wd. On hard acceleration it is bogging down like there is to much air, because sometimes it backfires. Or a plugged exhaust. I replaced the fuel pump-because it was bad in July. And with that the Fuel Filter. The wiring, and screen with the pump, in the tank. And also the throttle position sensor because for some odd ...From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Jul 03, 2011 · As it gets under load in higher gears it starts to sputter bad, especially in 3rd gear right before shifting into 4th (700r4 trans) Engine is a 10.5:1 compression (flat top pistons) 350 Chevy that's freshly rebuilt and is run on 93 oct gas, ignition timing is set at 10-12° idle, 700 rpm, and 34-36° at 3500 rpm. Mar 31, 2022 · hey guys new distributor complete, timing is spot on fuel pressure is great the usual pattern coming out of the injectors as i put it in gear hog on the brakes and give it throttle and after a certain rpm when it gets up there it starts stumbling, no popping sounds or anything like that, just stumbling and power loss with excellent fuel flow … May 08, 2014 · What you are describing sounds like spark knock (pinging). check your timing, you'll get pinging if it's advanced too far. lack of egr flow and a hot running engine can also cause this. too lean fuel mixture also causes high cylinder temps which causes spark knock. A alexa0908 Registered Joined May 8, 2014 3 Posts 1) The float level and drop both need to be looked at one is too low to where the force in the jets is insufficient, drop is not enough feed valve opening to keep the fuel level high enough when the throttle is wide open. 2) The main jets are too small. 3) The metering rods are too big. 4) The secondary jets are too small.Apr 28, 2008 · Vacuum advance goes away under load. I run 15 to 20 initial then run the vacuum advance connected to the manifold for a total of 30 to 35 at idle. This allows me to close the throttle plates much tighter and lean out the mixture at idle. picked up 2 inhg at idle with this setup. Plus it makes the throttle response much better. I have a 97 Suburban 5.7, 2wd. On hard acceleration it is bogging down like there is to much air, because sometimes it backfires. Or a plugged exhaust. I replaced the fuel pump-because it was bad in July. And with that the Fuel Filter. The wiring, and screen with the pump, in the tank. And also the throttle position sensor because for some odd ...Aug 12, 2014 · I have a 1968 camaro RS with a 350 I built and have had on the road for about 2 years now. The car used to run like crap, but fixed that issue by increasing the jet size from 65/68 to 69/73. Now the car runs much better, but still has two small problems. The first is a problem at part throttle under very low load (flat ground, 1800-2400 rpm). Joined Feb 5, 2004. 401 Posts. Discussion Starter · #1 · Sep 27, 2008. I have a 96 S-10, with the stock 2.2L and 5 speed tranny. It just started doing this today. When I am accelerating, the engine starts to sputter. It's worse when I get up into 3rd and 4th gear and give it more gas. If I put it in neutral and rev the engine, it revs just fine.Opening the throttle will open the throttle plates and will cause a lot of air to enter the engine. To overcome the lag of fuel delivery, there is an accelerator pump that squirts fuel into the venturi, or bore of the carburetor. If the accelerator pump does not operate properly, the engine may not start or will stumble badly on acceleration.Nov 28, 2011 · 350 chevy - bored .030" over 11:1 compression L98 Aluminum heads 58cc Edelbrock Streetmaster intake. Low rise single plane Holley Truck avenger 670 cfm carb. 69 Jets front 6.5" Pv 89 jets rear and 31# squirter MSD Streetfire Hei distributor. New with Taylor spiro pro wires. 14° idle and 35° at 3000 rpm. Running fp should be about 6-7psi ,under load wide open 3-5 for sure. Get the timing where it should be to eliminate any questions, clogged sock in the tank causes issues also. Martin86 11-27-2014, 12:35 PM I think you should take a longer trip and make shure you let it fully warm up before timing it.Hesitation Under Load. A hesitation, stumble or misfire that occurs when the engine is under load can be caused by a faulty power valve inside the carburetor. A carburetor uses intake vacuum to pull fuel through its metering circuits. As engine load increases and the throttle opens wider, intake vacuum drops. This can reduce the flow of fuel ...1988 CHEVROLET TRUCK V8 4WD MANUAL 200,000 MILES Fuel filter is new, 350 engine, throttle body injection will chug and miss under load when engine warms up but runs fine at idle. Feels like electrical to me, but who knows. Engine light does not come on. SPONSORED LINKS Do you have the same problem? Yes No Monday, September 14th, 2009 AT 9:57 PMSilveraodo Hesitation Issue..., Automotive, 18 replies Chevy/GMC 1500 Pickup 5.3 V8, Chevrolet, Cadillac, Buick, and GMC, 8 replies Lincoln Mark VIII hesitation, Ford and Lincoln, 8 replies Where can I find info on the 1988-1998 Chevy pickup truck V8 engines?, Automotive, 2 replies Fuel mileage Chevy pickup, Automotive, 4 repliesFrom idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Jun 10, 2021 · Vacuum advance is not likely the culprit since it is not present under load (low vacuum condition). You should rule it out though. Never assume. Here is what I would do... 1) Disconnect the vacuum advance and plug the port on your carburetor. Check your initial and total timing. Nov 28, 2011 · 350 chevy - bored .030" over 11:1 compression L98 Aluminum heads 58cc Edelbrock Streetmaster intake. Low rise single plane Holley Truck avenger 670 cfm carb. 69 Jets front 6.5" Pv 89 jets rear and 31# squirter MSD Streetfire Hei distributor. New with Taylor spiro pro wires. 14° idle and 35° at 3000 rpm. These misfires do often come under load from the engine, like when you are accelerating hard. The most common situation to notice misfires is on high gears, low RPM, and the accelerator to the floor. Rough acceleration is a typical sign that your engine is misfiring. 2. Rough IdleHad a similar thing happen and it ended up being a hole in the water jacket. Was a small leak in the top of the cylinder. Would run fine off the hose in the back yard but under load would crumble. Ended up replacing the engine for a newer 1. Apparently happens a fair bit at the cylinder closest to the water.Jan 25, 2015. #12. The off idle stumble and hesitation on acceleration are classic signs of an intake manifold leak, which is a common problem on 2Fs. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. sggoat, ErikinSC and Solace in Solitude.1993 chevy camaro z28 with a drivability problem not setting any codes, it have a stumble and weak power under load conditions problem not present will in closed loop (cold) ... I have an 89 chevy k2500 silverado 4x4, 350 engine, auto trans, ac, ps, pb with 180 thousand miles. It runs great down the road but idles rough.If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. I am having a misfire under load problem. The motor only has about 20 miles on it. I know the following about the motor / set up: 383 stroker Scat crank Scat rods Hyper pistons Approx. 10.8 - 1 CR Pro Comp Aluminum heads 190 cc Pro Products performer style intake Demon 750 vac. sec. carb Roller rockers Approx. 500 lift roller cam Hei dizzywolfen1086. Moderator, Automotive Team. Joined Oct 4, 2007. 13,890 Posts. #3 · Nov 19, 2011. the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from. K.Aug 26, 2009 · Easier yet, the common problem is the distributor pickup, located under the distributor cap. These little pitas can cause all kinds of hell. When they start to go bad, stumbling under load occurs. When they finally give up, you will have ZERO injector pulse or power to the coil. Any parts store carries these, about 35-45$$, I carry a spare now... Jan 25, 2015. #12. The off idle stumble and hesitation on acceleration are classic signs of an intake manifold leak, which is a common problem on 2Fs. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. sggoat, ErikinSC and Solace in Solitude.If you think the transmission could be slipping you might try a stall test. Set the park brake, hold the foot brake, and try to quickly rev the engine while the transmission is in DRIVE. (NOT Overdrive) The engine should stall out at around 2000 RPM give or take. Do this test quickly and don't beat it to death.Jun 02, 2008 · Along with the erratic idle, the engine has absolutely zero power. It stumbles as if it's missing a couple of cylinders when you accelerate. It has a hard time with ANY load (even the A/C compressor). I checked all of the wires and they are all good and tight on the plugs. Also made sure that they are going to the right cylinders. 134 Posts. #6 · Dec 14, 2004. Bogging past half throttle. Check the ignition timing. Change the fuel filter. Change the plugs, plug wires, disributor and rotor button. Do a system analisis to see if one or more of the half dozen or so sensors is bad. Put some injector cleaner in the fuel tank. Check for vacum leaks.sure, 20 at idle. but the second to hit the throttle and load up the engine the vacuum advance drops off (back to 8), which makes it bog. You need more mechanical timing. Vacuum advance goes away under load. I run 15 to 20 initial then run the vacuum advance connected to the manifold for a total of 30 to 35 at idle.Dec 24, 2005 · It is worse when under load. Hei is hooked to ported vacum on the carb. Initial timing is 10-12 Deg Full (total) timing is 22 deg I don't think the Vacum adv is working (New vac mod) Idle is set at about 600-650 RPM ( Guessing!! no tach) Any thought Oh yeh it will fire through the carb. Somtimes when you stomp the pedal in park and want to die. Removing the Chevy Six 250 Engine From the 1967 Van Saturday July 9, 2016 Guerneville CA. This engine has a… (2,647) Dirt Bike Forest Fire Ride and No Armstrong Woods… Friday August 21, 2020 Guerneville CA. Another forest fire day… (2,641) 1967 Chevy Van V8 350 Engine Conversion Wiring Saturday August 20, 2016 Guerneville CA. Engine ...My 1995 Chevrolet Silverado truck had a hesitation problem, which we were able to fix by replacing some parts. My Chevrolet truck would idle fine and passed ... I am having a misfire under load problem. The motor only has about 20 miles on it. I know the following about the motor / set up: 383 stroker Scat crank Scat rods Hyper pistons Approx. 10.8 - 1 CR Pro Comp Aluminum heads 190 cc Pro Products performer style intake Demon 750 vac. sec. carb Roller rockers Approx. 500 lift roller cam Hei dizzyDec 26, 2009 · I have a 1994 Chevy 350 , upon attempting to accelerate there is a lot of hesitation or sputtering from the motor. Thought it was a dirty carb or water in the gas but thats not it. Was told by a frend that it could be a bad distributor cap and rotor , any comments on this diagnosis ? The truck has 120 K miles on it Answered in 2 minutes by: July 25, 2013 in General Cadillac Forums. Share. Followers 1. High RPM misfire. The car will start and run fine, but will stop running anywhere from seconds to minutes later. The engine may not restart immediately but if left to cool for about 10 minutes will start fine. Hesitation/misfire under acceleration. Failure to start.Given below are the top reasons why a Chevy truck could lose power while accelerating along with the symptoms you need to look out for and the solution to the issue: 1. Bad Fuel Pump. Your Chevy Truck engine comes with a fuel pump that takes the gasoline from the fuel tank and transfers it to your truck's engine.wolfen1086. Moderator, Automotive Team. Joined Oct 4, 2007. 13,890 Posts. #3 · Nov 19, 2011. the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from. K.My 1995 Chevrolet Silverado truck had a hesitation problem, which we were able to fix by replacing some parts. My Chevrolet truck would idle fine and passed ... the o2 sensor is a used for fuel trim, if you continue to run the truck with a lean condition, your likely to burn a valve, but a vacuum leak can cause a lean condition, and with the rpm acting that way, i would really check for a hissing sound on all the vac hoses, intake manifold, power booster, ect.. it won't hurt to check the fuel pressure, …1.) with the air cleaner off, and engine off, actuate the throttle and see if the accel pump is squirting. 2.) ensuring the choke pull off isnt holding them, tap the secondary butterflys with your finger to open them. Now, unless you've played with QJets, like Mike up there who runs a dyno for Ford! , then you'll have no way of "feeling" it.Winging the throttle to 3k in neutral DOES NOT use as much fuel as it would when driving at 3k - a motor UNDER LOAD uses more fuel - your letting off the throttle supports this - since yuo are basically reducing the load and are definitely reducing the amount of AIR which makes your LEAN condition BETTER.From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Chevy silverado 5.7 350 hesitates under load!! Fixed 191,945 views Jan 6, 2016 551 Dislike Share Save Jmoney's garage 395 subscribers Chevy silverado 5.7 hesitates under load. This goes for all... Hesitation is when the engine stumbles, misfire or when you step on the throttle or you accelerate it lacks of power. The issue occurs most generally due the air/fuel mixture is going lean or isn't being enriched properly. Or when the air/fuel mixture going to lean or the engine comes under load, the ignition system is weak and misfiring.Nov 28, 2011 · 350 chevy - bored .030" over 11:1 compression L98 Aluminum heads 58cc Edelbrock Streetmaster intake. Low rise single plane Holley Truck avenger 670 cfm carb. 69 Jets front 6.5" Pv 89 jets rear and 31# squirter MSD Streetfire Hei distributor. New with Taylor spiro pro wires. 14° idle and 35° at 3000 rpm. Joined Jan 25, 2009. 731 Posts. #3 · Dec 16, 2009 (Edited) The 94 caprice that I service had similar problems like this, and after inspecting, the intake track had a crack in the bellows of the TB elbow. The crack wouldnt show until the engine was revved, and the movement of the engine would pull it open and bog the engine down.Mar 31, 2022 · Chevy. 91 TBI 350 gmc stumbles under load details inside. Jump to Latest Follow 1 - 1 of 1 Posts. FEandGoingBroke · Registered ... From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Another thing, get a vacuum guage to tune your mixture screws with. First, turn the screws out two full turns from bottom. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. Then counter-clockwise until the vacuum comes back up.Joined Feb 5, 2004. 401 Posts. Discussion Starter · #1 · Sep 27, 2008. I have a 96 S-10, with the stock 2.2L and 5 speed tranny. It just started doing this today. When I am accelerating, the engine starts to sputter. It's worse when I get up into 3rd and 4th gear and give it more gas. If I put it in neutral and rev the engine, it revs just fine.The Cheap rehab '79 Chevy truck is running pretty good, but still has a nagging misfire. A recent compression test and plug analysis reveals that the bottom ... 5,421 Posts. #7 · Dec 7, 2003. Well this is probably not it, but just another suggestion as a "last resort," Clint's 98 350 kept dying and it was because of a bad battery connection. It would be fine in park but as soon as you put it into any gear, it would die. Found out that the battery was not getting a good enough connection.499. The only true way to clean fuel injectors is with the kit that you buy. It plugs into the high pressure fuel pressure test fitting in the fuel rail and you run the engine off of the tank of cleaner that you get in the kit. Take the truck to Auto Zone and they will plug into the computer and read any codes for you. brown vomit after drinking Check the back fuel bowl and see if its getting gas in the bowl at all. sounds like its running on bad gas , so i'd check the timing as was mentioned. If it sounds good at idle , but not under load , thats usually fuel delivery , or too much timing related, or quality of your fuel. i'd take a timing light and go around the cap checking each ...1) The float level and drop both need to be looked at one is too low to where the force in the jets is insufficient, drop is not enough feed valve opening to keep the fuel level high enough when the throttle is wide open. 2) The main jets are too small. 3) The metering rods are too big. 4) The secondary jets are too small.Replied by Steven1980 on topic 1998 chevy k1500 5.7 vortec misfire. one more thing all the spark plugs are 3 months old and all 8 spark plugs have a brownish blackish tarry streak down the sides of the porcelain below the electrode and its just a streak maybe 1/8 to 1/4 wide that travels to the bottom of the porcelain and the rest of the ...Hesitation is when your engine misfires, stumbles or lacks power when you accelerate or step on the throttle. The problem often means the air/fuel mixture is not being properly enriched or is going lean, or the ignition system is weak and is misfiring when the engine comes under load or the air/fuel mixture goes lean.Had a similar thing happen and it ended up being a hole in the water jacket. Was a small leak in the top of the cylinder. Would run fine off the hose in the back yard but under load would crumble. Ended up replacing the engine for a newer 1. Apparently happens a fair bit at the cylinder closest to the water.If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. Replied by Steven1980 on topic 1998 chevy k1500 5.7 vortec misfire. one more thing all the spark plugs are 3 months old and all 8 spark plugs have a brownish blackish tarry streak down the sides of the porcelain below the electrode and its just a streak maybe 1/8 to 1/4 wide that travels to the bottom of the porcelain and the rest of the ...July 25, 2013 in General Cadillac Forums. Share. Followers 1. High RPM misfire. The car will start and run fine, but will stop running anywhere from seconds to minutes later. The engine may not restart immediately but if left to cool for about 10 minutes will start fine. Hesitation/misfire under acceleration. Failure to start.Top 10 Reasons Your Car Hesitates When Accelerating or Driving 1) Bad Throttle Position Sensor 2) Vacuum Leak 3) Faulty Fuel System 4) Faulty Ignition System 5) Dirty Fuel Injectors 6) Bad Oxygen Sensor 7) Faulty Mass Air Flow Sensor 8) Bad Manifold Absolute Pressure Sensor 9) Faulty Exhaust Gas Recirculation Valve 10) Bad Fuelthe o2 sensor is a used for fuel trim, if you continue to run the truck with a lean condition, your likely to burn a valve, but a vacuum leak can cause a lean condition, and with the rpm acting that way, i would really check for a hissing sound on all the vac hoses, intake manifold, power booster, ect.. it won't hurt to check the fuel pressure, …I have a 1999 GMC Yukon with a Vortec engine and 130,000 miles. My issue first showed up at 35,000 miles and has shown up from time to time since then, getting progressively worse. Sometimes, the Yukon would start to misfire when towing and occasionally when just going up a hill around 70 mph. The truck would start to shudder and shake and even ...Running too rich - High negative fuel trim corrections can be caused by MAF sensor problems, high fuel pressure, leaking fuel pressure regulator diaphragm, faulty evaporative emissions components, leaking injectors, defective O2 sensors, exhaust leaks/pinholes before the O2 sensor, coolant temp sensor problems, and base engine issues such as low compression and incorrect camshaft timing.5,421 Posts. #7 · Dec 7, 2003. Well this is probably not it, but just another suggestion as a "last resort," Clint's 98 350 kept dying and it was because of a bad battery connection. It would be fine in park but as soon as you put it into any gear, it would die. Found out that the battery was not getting a good enough connection.If you think the transmission could be slipping you might try a stall test. Set the park brake, hold the foot brake, and try to quickly rev the engine while the transmission is in DRIVE. (NOT Overdrive) The engine should stall out at around 2000 RPM give or take. Do this test quickly and don't beat it to death.Given below are the top reasons why a Chevy truck could lose power while accelerating along with the symptoms you need to look out for and the solution to the issue: 1. Bad Fuel Pump. Your Chevy Truck engine comes with a fuel pump that takes the gasoline from the fuel tank and transfers it to your truck's engine.From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Dec 22, 2017 · Ask Your Own Chevy Question Roy Belding ok possible casues are 1. low fuel pressure 2. ignition timing not set to spec. 3. clogged fuel filter 4. clogged cat converter Roy Ask Your Own Chevy Question Goodmorning Roy. I checked engine running fuel pressure is at about 13 psi. Base timing at 0 and i forget....maybe 6 or 8 degrees otherwise.. During the initial test drive, it developed a sputtering under load. It still shifted through all three gears (TH350) when cruising, but if you put mild to moderate pressure on the accelerator, it will sputter and act like it's starving for gas. This has not happened before.At lower throttle settings, the intake manifold has significant vacuum as the engine keeps pumping air and the throttle plate is at least partially closed. The pressure inside the manifold that feeds into the intake valve is less than atmospheric pressure. This is a less dense charge, and ignites easily.Jan 25, 2015. #12. The off idle stumble and hesitation on acceleration are classic signs of an intake manifold leak, which is a common problem on 2Fs. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. sggoat, ErikinSC and Solace in Solitude.Dec 22, 2017 · Ask Your Own Chevy Question Roy Belding ok possible casues are 1. low fuel pressure 2. ignition timing not set to spec. 3. clogged fuel filter 4. clogged cat converter Roy Ask Your Own Chevy Question Goodmorning Roy. I checked engine running fuel pressure is at about 13 psi. Base timing at 0 and i forget....maybe 6 or 8 degrees otherwise.. Joined Feb 5, 2004. 401 Posts. Discussion Starter · #1 · Sep 27, 2008. I have a 96 S-10, with the stock 2.2L and 5 speed tranny. It just started doing this today. When I am accelerating, the engine starts to sputter. It's worse when I get up into 3rd and 4th gear and give it more gas. If I put it in neutral and rev the engine, it revs just fine.Dec 24, 2005 · It is worse when under load. Hei is hooked to ported vacum on the carb. Initial timing is 10-12 Deg Full (total) timing is 22 deg I don't think the Vacum adv is working (New vac mod) Idle is set at about 600-650 RPM ( Guessing!! no tach) Any thought Oh yeh it will fire through the carb. Somtimes when you stomp the pedal in park and want to die. Jun 02, 2008 · Along with the erratic idle, the engine has absolutely zero power. It stumbles as if it's missing a couple of cylinders when you accelerate. It has a hard time with ANY load (even the A/C compressor). I checked all of the wires and they are all good and tight on the plugs. Also made sure that they are going to the right cylinders. Usuallly weak spark cause a misfire under a load,the compression increases when you open the throttle and can snuff out a weak spark --the cap and rotor can cause this even if they look perfect,but spark plug wires that are cracked,burnt from lying on an exhaust manifold or header will do the same,so can plugs that are fouled,or a weak ignition coil or pickup coil,sometimes the ignition module ...Nov 18, 2011 · Tighten the nut another 3/4 turn.....in 1/4 turn increments. With breaker bar (or long ratchet) and correct sized socket on the harmonic balancer bolt, rotate the engine exactly 90 degrees in the direction of rotation. Carefully look for two more rocker arms that are even with each other and repeat the process used to adjust #1 cyl valves. Chevy 350 stumbles under load 7.3 Hesitation under normal conditions (Page EF & EC 79 in the manual) NEW Again, spark plugs, and PCV leaks and exhaust gas sensors, also referred to as oxygen sensors, are possible suspects here. (See sections 6. If the ECU turns up an OK result for the exhaust gas sensor, be careful, as it still may be faulty.May 08, 2014 · What you are describing sounds like spark knock (pinging). check your timing, you'll get pinging if it's advanced too far. lack of egr flow and a hot running engine can also cause this. too lean fuel mixture also causes high cylinder temps which causes spark knock. A alexa0908 Registered Joined May 8, 2014 3 Posts As it gets under load in higher gears it starts to sputter bad, especially in 3rd gear right before shifting into 4th (700r4 trans) Engine is a 10. ... Chevy TBI 350 stumbles on acceleration. Jun 20, 2016 · Accelerating requires more fuel, forcing your fuel pump to work harder. I used to have a 1957 Chevy truck that did that very same thing.Nov 18, 2011 · Tighten the nut another 3/4 turn.....in 1/4 turn increments. With breaker bar (or long ratchet) and correct sized socket on the harmonic balancer bolt, rotate the engine exactly 90 degrees in the direction of rotation. Carefully look for two more rocker arms that are even with each other and repeat the process used to adjust #1 cyl valves. 90Brougham350 Registered 94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold) Joined Jan 12, 2005 3,710 Posts #3 · Feb 26, 2006 500,000 miles? You need a new timing chain, and your timing is more than likely off, this is usually what causes backfires, but the stretched timing chain is more than likely making things worse.Replied by Steven1980 on topic 1998 chevy k1500 5.7 vortec misfire. one more thing all the spark plugs are 3 months old and all 8 spark plugs have a brownish blackish tarry streak down the sides of the porcelain below the electrode and its just a streak maybe 1/8 to 1/4 wide that travels to the bottom of the porcelain and the rest of the ...Opening the throttle will open the throttle plates and will cause a lot of air to enter the engine. To overcome the lag of fuel delivery, there is an accelerator pump that squirts fuel into the venturi, or bore of the carburetor. If the accelerator pump does not operate properly, the engine may not start or will stumble badly on acceleration.Joined Jun 4, 2010. 560 Posts. #7 · Feb 25, 2011. Re: chevy 1500 backfire. not hard at all just takes 2 ppl. remove the dist cap with a socket on a breaker bar connected to the crank shaft front bolt turn it backwards a little when the second guy sees the rotor turn you can stop mark the balancer with a reference point on the timing mark ...Mar 21, 2009 · It has a period 350 with single hump heads, HEI distributor, MSD Ignition, headers,very mild or stock cam, and a carter AFB comp carb. TH350 tranny The car starts real good, idles real good. But it feels really low on power and has a miss under load. It revs up fairly clean when sitting still, and its not as bad in first. 625 Scott answered 12 years ago check the ignition timing. you have to find the spout connector to force the computer to stop advancing the timing and set at base then make sure the engine is at operating temp and idling properly. then find your timing marks with the light and adjust it if needed. 34 people found this helpful. Mark helpful 755Nov 28, 2011 · 350 chevy - bored .030" over 11:1 compression L98 Aluminum heads 58cc Edelbrock Streetmaster intake. Low rise single plane Holley Truck avenger 670 cfm carb. 69 Jets front 6.5" Pv 89 jets rear and 31# squirter MSD Streetfire Hei distributor. New with Taylor spiro pro wires. 14° idle and 35° at 3000 rpm. Dec 22, 2017 · Timing wire unplugged 0 degree.... Tps less than 4 @ idle....4 with increased idle I believe. Chevy Mechanic: Roy Belding. tps should be .5 to .75 volts at idle and increase according to pedal up to 4.8. timing should be set to 6 to 8 degrees. you have retarded timing at this point. Roy. Aug 21, 2019 · It will start normally and idle fine (with a barely noticeable misfire). It behaves pretty well until it starts to warm up. After warming, the engine starts missing significantly when I give it a little throttle (neutral or in gear). If I keep a light throttle in neutral the miss will get worse until it barely keeps going. Opening the throttle will open the throttle plates and will cause a lot of air to enter the engine. To overcome the lag of fuel delivery, there is an accelerator pump that squirts fuel into the venturi, or bore of the carburetor. If the accelerator pump does not operate properly, the engine may not start or will stumble badly on acceleration.Joined Jan 25, 2009. 731 Posts. #3 · Dec 16, 2009 (Edited) The 94 caprice that I service had similar problems like this, and after inspecting, the intake track had a crack in the bellows of the TB elbow. The crack wouldnt show until the engine was revved, and the movement of the engine would pull it open and bog the engine down.1. Excessive Oil Consumption. One of the most common 2007-2013 GMC and Chevy truck problems owners experience is excessive oil consumption. This problem led vehicle buyers to launch a class-action lawsuit against GM, which alleged 2010-2013 vehicles with Generation IV 5.3 Liter V8 Vortec 5300 engines were defective.These misfires do often come under load from the engine, like when you are accelerating hard. The most common situation to notice misfires is on high gears, low RPM, and the accelerator to the floor. Rough acceleration is a typical sign that your engine is misfiring. 2. Rough IdleSeems to idle smoothly but pretty rich, and while driving the engine often cuts out and then after a second or two with my foot off of the throttle the engine will cut back in. This will happen repeatedly once it starts, uphill or flat, and regardless of fuel level in the tank. New plugs, wires, mechanical fuel pump, fuel filter, air cleaner. Nov 28, 2011 · 350 chevy - bored .030" over 11:1 compression L98 Aluminum heads 58cc Edelbrock Streetmaster intake. Low rise single plane Holley Truck avenger 670 cfm carb. 69 Jets front 6.5" Pv 89 jets rear and 31# squirter MSD Streetfire Hei distributor. New with Taylor spiro pro wires. 14° idle and 35° at 3000 rpm. Chevy 350 stumbles under load 7.3 Hesitation under normal conditions (Page EF & EC 79 in the manual) NEW Again, spark plugs, and PCV leaks and exhaust gas sensors, also referred to as oxygen sensors, are possible suspects here. (See sections 6. If the ECU turns up an OK result for the exhaust gas sensor, be careful, as it still may be faulty.Aug 12, 2014 · I have a 1968 camaro RS with a 350 I built and have had on the road for about 2 years now. The car used to run like crap, but fixed that issue by increasing the jet size from 65/68 to 69/73. Now the car runs much better, but still has two small problems. The first is a problem at part throttle under very low load (flat ground, 1800-2400 rpm). Running too rich - High negative fuel trim corrections can be caused by MAF sensor problems, high fuel pressure, leaking fuel pressure regulator diaphragm, faulty evaporative emissions components, leaking injectors, defective O2 sensors, exhaust leaks/pinholes before the O2 sensor, coolant temp sensor problems, and base engine issues such as low compression and incorrect camshaft timing.Chevy small block cylinder misfire/rough acceleration. Am I an idiot? My 1986 Silverado C10 with a small block 305 is having a weird misfire issue. At idle it has a slight miss, and under load any sort of load or while accelerating through mid range RPMs, it runs like absolute crap and will even feel like a shutter at times. It feels like a ...Top 6 Bad Throttle Position Sensor Symptoms 1) Car Jerks 2) Idle Surging 3) Check Engine Light 4) Engine Stalling 5) Acceleration Issues 6) Problems Switching Gears Can You Fix a Bad Throttle Position Sensor? Throttle Position Sensor Replacement Cost Can You Drive With a Bad TPS? What Does a Throttle Position Sensor Do?Oct 07, 2013 · Thank you for the help! Specs: 1978 block 350 bored .060 over. holley alum heads 2.02/1.60 valves. 9-9.5:1 compression. Holley 670 cfm street avenger carb w/ Vac Sec. and elec. choke 65 pri and 68 sec using 'middle' spring. lunati .477-.507 lift 225-235*@.050 duration 112* lobe separtion cam. 90Brougham350 Registered 94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold) Joined Jan 12, 2005 3,710 Posts #3 · Feb 26, 2006 500,000 miles? You need a new timing chain, and your timing is more than likely off, this is usually what causes backfires, but the stretched timing chain is more than likely making things worse.the o2 sensor is a used for fuel trim, if you continue to run the truck with a lean condition, your likely to burn a valve, but a vacuum leak can cause a lean condition, and with the rpm acting that way, i would really check for a hissing sound on all the vac hoses, intake manifold, power booster, ect.. it won't hurt to check the fuel pressure, …Jun 10, 2021 · The car/engine (specs are at the end of this post) bogs down under load. Specifically, when I give it gas, the engine initially responds normally, but then bogs down/stumbles. Then, I give it a bit more gas. Again, the engine initially responds normally, but then bogs down. The engine runs fine idling and when I give it gas with the trans in ... If you think the transmission could be slipping you might try a stall test. Set the park brake, hold the foot brake, and try to quickly rev the engine while the transmission is in DRIVE. (NOT Overdrive) The engine should stall out at around 2000 RPM give or take. Do this test quickly and don't beat it to death.Mar 21, 2009 · It has a period 350 with single hump heads, HEI distributor, MSD Ignition, headers,very mild or stock cam, and a carter AFB comp carb. TH350 tranny The car starts real good, idles real good. But it feels really low on power and has a miss under load. It revs up fairly clean when sitting still, and its not as bad in first. Engine hesitates during acceleration Inspection. Estimate. $94.99. Shop/Dealer Price. $105.01 - $112.52. 1998 Chevrolet Camaro V6-3.8L. Service type. Engine hesitates during acceleration Inspection. Estimate.Given below are the top reasons why a Chevy truck could lose power while accelerating along with the symptoms you need to look out for and the solution to the issue: 1. Bad Fuel Pump. Your Chevy Truck engine comes with a fuel pump that takes the gasoline from the fuel tank and transfers it to your truck's engine.Having the timing advanced or retarded will cause problems, including hesitation, bogging or even misfire. Unplug the tan/black wire, time the engine to ZERO degrees and reconnect the tan/black wire. Logged. 1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80. 1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF. Retarding the timing just seems to make the engine sputter and want to die at idle under load and under no load. The problem is now bad enough to where if you don't keep it alive when you throw it in drive by using the throttle, it dies within seconds. Last edited: Sep 8, 2015. Sep 8, 2015.At lower throttle settings, the intake manifold has significant vacuum as the engine keeps pumping air and the throttle plate is at least partially closed. The pressure inside the manifold that feeds into the intake valve is less than atmospheric pressure. This is a less dense charge, and ignites easily.Discussion Starter · #5 · Jan 20, 2014. the fluid is new. when i got the car i threw in new fluid and filter. the motor cuts in and out not the trans. its kind of like if you floor it and you kill the power and then turn the power on and off then on and then off then on and off. but if you let off the gas then it will idle fine no problem ...Oct 07, 2013 · 1978 block 350 bored .060 over holley alum heads 2.02/1.60 valves 9-9.5:1 compression Holley 670 cfm street avenger carb w/ Vac Sec. and elec. choke 65 pri and 68 sec using 'middle' spring lunati .477-.507 lift 225-235*@.050 duration 112* lobe separtion cam 4* deg advance of the cam w/ relation to crank m21 4 spd long tube headers 3.08 gears Nov 18, 2011 · wolfen1086. Moderator, Automotive Team. Joined Oct 4, 2007. 13,890 Posts. #3 · Nov 19, 2011. the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from. K. Back firing. 10-19-2016, 04:16 PM. 1964 Impala sbc 283 .040 over edelbrock thunder avs 500 cfm carb, performer EPS intake, refurbed H.O. 305 heads (I think they are only off 2cc from stock) and 204° / 214° .420" / .442" 112° 107° on the cam with msd 8360 distributor and street fire wires. Vacuum was around 13-14.Gauges are $20. Specis 60-66psi at Key On ENgine Off (KOEO) Key On Engine Running will be slightly less. Could be a vacuum leak, take some brake cleaner and spray it around all selaing points of the intake. If the engine idle changes, you have an issue.Feb 09, 2011 · Discussion Starter · #1 · Feb 9, 2011. Hey guys, I finally got my 350 up and running, she purrs like a kitten and is stronger than EVER! I have 70 to 75 pounds oil pressure cold and 40 - 45 warm and 70 pounds when i get on the pedal! Although im having trouble with the tbi i assume. the engine will stall when coming to stop at a stop light ... Dec 24, 2005 · It is worse when under load. Hei is hooked to ported vacum on the carb. Initial timing is 10-12 Deg Full (total) timing is 22 deg I don't think the Vacum adv is working (New vac mod) Idle is set at about 600-650 RPM ( Guessing!! no tach) Any thought Oh yeh it will fire through the carb. Somtimes when you stomp the pedal in park and want to die. I have a 1999 GMC Yukon with a Vortec engine and 130,000 miles. My issue first showed up at 35,000 miles and has shown up from time to time since then, getting progressively worse. Sometimes, the Yukon would start to misfire when towing and occasionally when just going up a hill around 70 mph. The truck would start to shudder and shake and even ...Dec 26, 2009 · I have a 1994 Chevy 350 , upon attempting to accelerate there is a lot of hesitation or sputtering from the motor. Thought it was a dirty carb or water in the gas but thats not it. Was told by a frend that it could be a bad distributor cap and rotor , any comments on this diagnosis ? The truck has 120 K miles on it Answered in 2 minutes by: Usuallly weak spark cause a misfire under a load,the compression increases when you open the throttle and can snuff out a weak spark --the cap and rotor can cause this even if they look perfect,but spark plug wires that are cracked,burnt from lying on an exhaust manifold or header will do the same,so can plugs that are fouled,or a weak ignition coil or pickup coil,sometimes the ignition module ...Some customers may comment on a 1-2 shift shudder at light to moderate acceleration. Typically, the throttle plate angle parameter is 12-20% at time of condition with vehicle speed of approximately 24-40 km/h (15-25 mph). The customer may describe the condition as slip or delayed shift into second. Correction. best rice coal stove Aug 21, 2019 · It will start normally and idle fine (with a barely noticeable misfire). It behaves pretty well until it starts to warm up. After warming, the engine starts missing significantly when I give it a little throttle (neutral or in gear). If I keep a light throttle in neutral the miss will get worse until it barely keeps going. Aug 12, 2014 · I have a 1968 camaro RS with a 350 I built and have had on the road for about 2 years now. The car used to run like crap, but fixed that issue by increasing the jet size from 65/68 to 69/73. Now the car runs much better, but still has two small problems. The first is a problem at part throttle under very low load (flat ground, 1800-2400 rpm). Jun 11, 2012 · Slowly, it will drop 1-200 rpms, hold for a few seconds, then drop another 1-200rpms, continuing until i let off to about 3/4 throttle. The main issue is while towing with this tired 350, i need EVERYTHING its got to make it up some grades. Dec 15, 2009 · Joined Jan 25, 2009. 731 Posts. #3 · Dec 16, 2009 (Edited) The 94 caprice that I service had similar problems like this, and after inspecting, the intake track had a crack in the bellows of the TB elbow. The crack wouldnt show until the engine was revved, and the movement of the engine would pull it open and bog the engine down. Jan 28, 2009 · The two most common causes of hesitation on these vehicles are Throttle position sensor and MAP sensors. Both can be checked with a lab scope, but aon a truck this old you have to weigh whether the money is better spent on two new components rather than testing costs. The Cheap rehab '79 Chevy truck is running pretty good, but still has a nagging misfire. A recent compression test and plug analysis reveals that the bottom ... The car hesitates and stumbles, but give her a little more gas and she takes off. Well, thought it may have been just the old engine. Put a new GM Performance 290 HP 350, GM Performance mechanical fuel pump, MSD distributor and ignition, wires, plugs and a K&N air cleaner. We transferred the new Edelbrock intake and carb to the new engine.Aug 21, 2019 · It will start normally and idle fine (with a barely noticeable misfire). It behaves pretty well until it starts to warm up. After warming, the engine starts missing significantly when I give it a little throttle (neutral or in gear). If I keep a light throttle in neutral the miss will get worse until it barely keeps going. There should be no EGR flow at idle, only under load. That said, since the issue is under load, that would normally indicate a problem with the ignition system since it will likely fail under load but it sounds like you've covered most of the parts on the ignition system. This leaves fuel delivery. The old TBI systems could be tricky.Jul 03, 2011 · As it gets under load in higher gears it starts to sputter bad, especially in 3rd gear right before shifting into 4th (700r4 trans) Engine is a 10.5:1 compression (flat top pistons) 350 Chevy that's freshly rebuilt and is run on 93 oct gas, ignition timing is set at 10-12° idle, 700 rpm, and 34-36° at 3500 rpm. I have a 79 chevy 3/4 ton pickup with a fresh 350 bored 40 over it has an edelbrock rpm air gap intake, edelbrock 600 cfm carb, headers, accel coil, and cranes power max cam with an advertised duratio …Replied by Steven1980 on topic 1998 chevy k1500 5.7 vortec misfire. one more thing all the spark plugs are 3 months old and all 8 spark plugs have a brownish blackish tarry streak down the sides of the porcelain below the electrode and its just a streak maybe 1/8 to 1/4 wide that travels to the bottom of the porcelain and the rest of the ...Feb 09, 2011 · Discussion Starter · #1 · Feb 9, 2011. Hey guys, I finally got my 350 up and running, she purrs like a kitten and is stronger than EVER! I have 70 to 75 pounds oil pressure cold and 40 - 45 warm and 70 pounds when i get on the pedal! Although im having trouble with the tbi i assume. the engine will stall when coming to stop at a stop light ... Jun 11, 2012 · Slowly, it will drop 1-200 rpms, hold for a few seconds, then drop another 1-200rpms, continuing until i let off to about 3/4 throttle. The main issue is while towing with this tired 350, i need EVERYTHING its got to make it up some grades. Engine misses at around 2500-3300 RPM. Robs_232 Member Posts: 212 . September 2014 in Engine Discussions.1987 CHEVROLET TRUCK. 175,000 MILES. My chevy 1987 chevy Scottsdale with a 350 tbi sometime runs smooth then sometimes runs like its running with half the power or less like it has bad gas or something. I have replaced the fuel filter, oxygen sensor, air filter, it doesn't matter which tank I run it on, I've used fuel dryer (Heat) changed pvc ...Manifold vacuum pressure is highest with the throttle plates are closed and the vehicle is idling. At this time there is no ported vacuum pressure. The throttle plates create a ported signal once they open and air flows past the base plate of the carburetor. Deteriorated or broken vacuum lines can create the same symptoms as a malfunctioning ...Aug 21, 2019 · It will start normally and idle fine (with a barely noticeable misfire). It behaves pretty well until it starts to warm up. After warming, the engine starts missing significantly when I give it a little throttle (neutral or in gear). If I keep a light throttle in neutral the miss will get worse until it barely keeps going. Dec 26, 2009 · I have a 1994 Chevy 350 , upon attempting to accelerate there is a lot of hesitation or sputtering from the motor. Thought it was a dirty carb or water in the gas but thats not it. Was told by a frend that it could be a bad distributor cap and rotor , any comments on this diagnosis ? The truck has 120 K miles on it Answered in 2 minutes by: If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. quadra counseling Winging the throttle to 3k in neutral DOES NOT use as much fuel as it would when driving at 3k - a motor UNDER LOAD uses more fuel - your letting off the throttle supports this - since yuo are basically reducing the load and are definitely reducing the amount of AIR which makes your LEAN condition BETTER.There should be no EGR flow at idle, only under load. That said, since the issue is under load, that would normally indicate a problem with the ignition system since it will likely fail under load but it sounds like you've covered most of the parts on the ignition system. This leaves fuel delivery. The old TBI systems could be tricky.During the initial test drive, it developed a sputtering under load. It still shifted through all three gears (TH350) when cruising, but if you put mild to moderate pressure on the accelerator, it will sputter and act like it's starving for gas. This has not happened before.I have a 1999 GMC Yukon with a Vortec engine and 130,000 miles. My issue first showed up at 35,000 miles and has shown up from time to time since then, getting progressively worse. Sometimes, the Yukon would start to misfire when towing and occasionally when just going up a hill around 70 mph. The truck would start to shudder and shake and even ...I have a 79 chevy 3/4 ton pickup with a fresh 350 bored 40 over it has an edelbrock rpm air gap intake, edelbrock 600 cfm carb, headers, accel coil, and cranes power max cam with an advertised duratio …Mar 31, 2022 · Chevy. 91 TBI 350 gmc stumbles under load details inside. Jump to Latest Follow 1 - 1 of 1 Posts. FEandGoingBroke · Registered ... 1990 chevy c1500 hesitation and stumbling during acceleration Unresponsive to gas peddle at times and has major dead spots. not sure if its the injectors or the timing or if i need a tps sensor Posted by Anonymous on Dec 04, 2012 problems so far: injectors shot turck was pissing gas the second the lines pressurized. 2. TPS code 22 low voltage 3.The Cheap rehab '79 Chevy truck is running pretty good, but still has a nagging misfire. A recent compression test and plug analysis reveals that the bottom ... Nov 18, 2011 · wolfen1086. Moderator, Automotive Team. Joined Oct 4, 2007. 13,890 Posts. #3 · Nov 19, 2011. the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from. K. It has a period 350 with single hump heads, HEI distributor, MSD Ignition, headers,very mild or stock cam, and a carter AFB comp carb. TH350 tranny The car starts real good, idles real good. But it feels really low on power and has a miss under load. It revs up fairly clean when sitting still, and its not as bad in first.Oct 07, 2013 · 1978 block 350 bored .060 over holley alum heads 2.02/1.60 valves 9-9.5:1 compression Holley 670 cfm street avenger carb w/ Vac Sec. and elec. choke 65 pri and 68 sec using 'middle' spring lunati .477-.507 lift 225-235*@.050 duration 112* lobe separtion cam 4* deg advance of the cam w/ relation to crank m21 4 spd long tube headers 3.08 gears If you think the transmission could be slipping you might try a stall test. Set the park brake, hold the foot brake, and try to quickly rev the engine while the transmission is in DRIVE. (NOT Overdrive) The engine should stall out at around 2000 RPM give or take. Do this test quickly and don't beat it to death.I have a 97 Suburban 5.7, 2wd. On hard acceleration it is bogging down like there is to much air, because sometimes it backfires. Or a plugged exhaust. I replaced the fuel pump-because it was bad in July. And with that the Fuel Filter. The wiring, and screen with the pump, in the tank. And also the throttle position sensor because for some odd ...Start at 4:51 if your in a hurry for a solution. A year worth of head scratching. Carburetor rebuild, throwing parts at, and uncertainty as to this truck bei...If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. Jul 18, 2011. 16. MN. I have an off idle stumble with my Edelbrock carb and cant seem to cure it. I am using an Innovate LM2 to help tune, everything is fine @ idle, under load, and WOT. It seems like when the carb goes from the idle system to the priamary main system it goes lean for a split second ( it shows on the LM2) and I get a hesitation ...Having the timing advanced or retarded will cause problems, including hesitation, bogging or even misfire. Unplug the tan/black wire, time the engine to ZERO degrees and reconnect the tan/black wire. Logged. 1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80. 1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF. Sep 21, 2016 · Other observations. 1. Problem is only under load. When in the water in neutral throttling in that rpm range is smooth and trouble free. 2. fuel tank air vent is clear. 3. vital signs at idle: engine runs at 168f, fuel pressure steady at 42.8, water pressure at 3.7, oil pressure 49.1. Another thing, get a vacuum guage to tune your mixture screws with. First, turn the screws out two full turns from bottom. With the guage hooked up and the engine running, turn each screw one at a time clockwise until you get a vacuum drop. Then counter-clockwise until the vacuum comes back up.If your car or truck is running poor under load, take a look at some of the simple solutions to get it running 100 percent. July 25, 2013 in General Cadillac Forums. Share. Followers 1. High RPM misfire. The car will start and run fine, but will stop running anywhere from seconds to minutes later. The engine may not restart immediately but if left to cool for about 10 minutes will start fine. Hesitation/misfire under acceleration. Failure to start.At lower throttle settings, the intake manifold has significant vacuum as the engine keeps pumping air and the throttle plate is at least partially closed. The pressure inside the manifold that feeds into the intake valve is less than atmospheric pressure. This is a less dense charge, and ignites easily. Start at 4:51 if your in a hurry for a solution. A year worth of head scratching. Carburetor rebuild, throwing parts at, and uncertainty as to this truck bei...Oct 07, 2013 · Thank you for the help! Specs: 1978 block 350 bored .060 over. holley alum heads 2.02/1.60 valves. 9-9.5:1 compression. Holley 670 cfm street avenger carb w/ Vac Sec. and elec. choke 65 pri and 68 sec using 'middle' spring. lunati .477-.507 lift 225-235*@.050 duration 112* lobe separtion cam. Nov 18, 2011 · Tighten the nut another 3/4 turn.....in 1/4 turn increments. With breaker bar (or long ratchet) and correct sized socket on the harmonic balancer bolt, rotate the engine exactly 90 degrees in the direction of rotation. Carefully look for two more rocker arms that are even with each other and repeat the process used to adjust #1 cyl valves. From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. During the initial test drive, it developed a sputtering under load. It still shifted through all three gears (TH350) when cruising, but if you put mild to moderate pressure on the accelerator, it will sputter and act like it's starving for gas. This has not happened before.297 Posts. #2 · May 8, 2014. Greetings and welcome aboard! What you are describing sounds like spark knock (pinging). check your timing, you'll get pinging if it's advanced too far. lack of egr flow and a hot running engine can also cause this. too lean fuel mixture also causes high cylinder temps which causes spark knock.My 1994 Chevy K1500 350. Sep 21, 2016 · Other observations. 1. Problem is only under load. When in the water in neutral throttling in that rpm range is smooth and trouble free. 2. fuel tank air vent is clear. 3. vital signs at idle: engine runs at 168f, fuel pressure steady at 42.8, water pressure at 3.7, oil pressure 49.1..90Brougham350 Registered 94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold) Joined Jan 12, 2005 3,710 Posts #3 · Feb 26, 2006 500,000 miles? You need a new timing chain, and your timing is more than likely off, this is usually what causes backfires, but the stretched timing chain is more than likely making things worse.499. The only true way to clean fuel injectors is with the kit that you buy. It plugs into the high pressure fuel pressure test fitting in the fuel rail and you run the engine off of the tank of cleaner that you get in the kit. Take the truck to Auto Zone and they will plug into the computer and read any codes for you.Feb 07, 2009 · I have a 79 chevy 3/4 ton pickup with a fresh 350 bored 40 over it has an edelbrock rpm air gap intake, edelbrock 600 cfm carb, headers, accel coil, and cranes power max cam with an advertised duratio … 2 Posts. #15 · Jan 2, 2015. i got a 05 raptor 350. it will start up just fine and if you give it more than half throttle it will spit and sputter and backfire then just die. if you catch it in time you can grab the clutch and feather the throttle and it will clear back up but if you ever let it cut off it takes a little bit to get it started ...Dec 26, 2009 · I have a 1994 Chevy 350 , upon attempting to accelerate there is a lot of hesitation or sputtering from the motor. Thought it was a dirty carb or water in the gas but thats not it. Was told by a frend that it could be a bad distributor cap and rotor , any comments on this diagnosis ? The truck has 120 K miles on it Answered in 2 minutes by: From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Nov 28, 2011 · 350 chevy - bored .030" over 11:1 compression L98 Aluminum heads 58cc Edelbrock Streetmaster intake. Low rise single plane Holley Truck avenger 670 cfm carb. 69 Jets front 6.5" Pv 89 jets rear and 31# squirter MSD Streetfire Hei distributor. New with Taylor spiro pro wires. 14° idle and 35° at 3000 rpm. Removing the Chevy Six 250 Engine From the 1967 Van Saturday July 9, 2016 Guerneville CA. This engine has a… (2,647) Dirt Bike Forest Fire Ride and No Armstrong Woods… Friday August 21, 2020 Guerneville CA. Another forest fire day… (2,641) 1967 Chevy Van V8 350 Engine Conversion Wiring Saturday August 20, 2016 Guerneville CA. Engine ...Engine hesitates during acceleration Inspection. Estimate. $94.99. Shop/Dealer Price. $105.01 - $112.52. 1998 Chevrolet Camaro V6-3.8L. Service type. Engine hesitates during acceleration Inspection. Estimate.had this problem on the 84's q-jet it was the carb starving the motor of fuel and only did it under load. I'd try another carb or check the filter/strainer in the inlet of the carb, we did that and changed the pump, put in an in line filter and blew air back thru to clean the fuel strainer in the tank and still got nothing, no vac. leaks, complete tune up and all, ended up putting on an ... Good evening. I am new to this forum and have a question. I have a 1995 Maxum SCR 2400 with a Mercuiser 5.7L V8. Had it out on the lake Saturday skiing with no problem for a couple hours. After a short break i tried to pull a skier up and could get no power. The engine would only rev up...499. The only true way to clean fuel injectors is with the kit that you buy. It plugs into the high pressure fuel pressure test fitting in the fuel rail and you run the engine off of the tank of cleaner that you get in the kit. Take the truck to Auto Zone and they will plug into the computer and read any codes for you.297 Posts. #2 · May 8, 2014. Greetings and welcome aboard! What you are describing sounds like spark knock (pinging). check your timing, you'll get pinging if it's advanced too far. lack of egr flow and a hot running engine can also cause this. too lean fuel mixture also causes high cylinder temps which causes spark knock.Engine hesitates during acceleration Inspection. Estimate. $94.99. Shop/Dealer Price. $105.01 - $112.52. 1998 Chevrolet Camaro V6-3.8L. Service type. Engine hesitates during acceleration Inspection. Estimate.297 Posts. #2 · May 8, 2014. Greetings and welcome aboard! What you are describing sounds like spark knock (pinging). check your timing, you'll get pinging if it's advanced too far. lack of egr flow and a hot running engine can also cause this. too lean fuel mixture also causes high cylinder temps which causes spark knock.Jun 10, 2021 · The car/engine (specs are at the end of this post) bogs down under load. Specifically, when I give it gas, the engine initially responds normally, but then bogs down/stumbles. Then, I give it a bit more gas. Again, the engine initially responds normally, but then bogs down. The engine runs fine idling and when I give it gas with the trans in ... 6,308. MN. The TPS on a TBI engine is not adjustable. You need to have a scanner of some sort to see the voltage and it should go from .5 to 4.5 at WOT. The voltage should look smooth with no voltage flat spots. One thing I do know that TBI engines do is hesitate from the EGR opening too soon.sure, 20 at idle. but the second to hit the throttle and load up the engine the vacuum advance drops off (back to 8), which makes it bog. You need more mechanical timing. Vacuum advance goes away under load. I run 15 to 20 initial then run the vacuum advance connected to the manifold for a total of 30 to 35 at idle.1) The float level and drop both need to be looked at one is too low to where the force in the jets is insufficient, drop is not enough feed valve opening to keep the fuel level high enough when the throttle is wide open. 2) The main jets are too small. 3) The metering rods are too big. 4) The secondary jets are too small.Engine hesitates during acceleration Inspection. Estimate. $94.99. Shop/Dealer Price. $105.01 - $112.52. 1998 Chevrolet Camaro V6-3.8L. Service type. Engine hesitates during acceleration Inspection. Estimate.Dec 24, 2005 · It is worse when under load. Hei is hooked to ported vacum on the carb. Initial timing is 10-12 Deg Full (total) timing is 22 deg I don't think the Vacum adv is working (New vac mod) Idle is set at about 600-650 RPM ( Guessing!! no tach) Any thought Oh yeh it will fire through the carb. Somtimes when you stomp the pedal in park and want to die. Usuallly weak spark cause a misfire under a load,the compression increases when you open the throttle and can snuff out a weak spark --the cap and rotor can cause this even if they look perfect,but spark plug wires that are cracked,burnt from lying on an exhaust manifold or header will do the same,so can plugs that are fouled,or a weak ignition coil or pickup coil,sometimes the ignition module ...Usuallly weak spark cause a misfire under a load,the compression increases when you open the throttle and can snuff out a weak spark --the cap and rotor can cause this even if they look perfect,but spark plug wires that are cracked,burnt from lying on an exhaust manifold or header will do the same,so can plugs that are fouled,or a weak ignition coil or pickup coil,sometimes the ignition module ...Retarding the timing just seems to make the engine sputter and want to die at idle under load and under no load. The problem is now bad enough to where if you don't keep it alive when you throw it in drive by using the throttle, it dies within seconds. Last edited: Sep 8, 2015. Sep 8, 2015.3,105. Aug 17, 2010. #8. Re: Chevy 350 Engine/Mercruiser 5.7 Problems!! I hope the gauge was wrong and you actually had oil in there. What I think I'd recommend is when you get your boat back from the shop, every time you get it back, do some basic checking on it yourself before you try to go on the water.If you think the transmission could be slipping you might try a stall test. Set the park brake, hold the foot brake, and try to quickly rev the engine while the transmission is in DRIVE. (NOT Overdrive) The engine should stall out at around 2000 RPM give or take. Do this test quickly and don't beat it to death.From idle, when you just ease down on the throttle it hesitates or bogs momentarily before finally accelerating. When you look at the timing, the advance is working but it is controlled by the esc. It doesn't advance until the engine gets to maybe 1200-1500 rpm. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. Aug 12, 2014 · I have a 1968 camaro RS with a 350 I built and have had on the road for about 2 years now. The car used to run like crap, but fixed that issue by increasing the jet size from 65/68 to 69/73. Now the car runs much better, but still has two small problems. The first is a problem at part throttle under very low load (flat ground, 1800-2400 rpm). Sep 26, 2017 · 1) The float level and drop both need to be looked at one is too low to where the force in the jets is insufficient, drop is not enough feed valve opening to keep the fuel level high enough when the throttle is wide open. 2) The main jets are too small. 3) The metering rods are too big. 4) The secondary jets are too small. The car/engine (specs are at the end of this post) bogs down under load. Specifically, when I give it gas, the engine initially responds normally, but then bogs down/stumbles. Then, I give it a bit more gas. Again, the engine initially responds normally, but then bogs down. The engine runs fine idling and when I give it gas with the trans in ...90Brougham350 Registered 94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold) Joined Jan 12, 2005 3,710 Posts #3 · Feb 26, 2006 500,000 miles? You need a new timing chain, and your timing is more than likely off, this is usually what causes backfires, but the stretched timing chain is more than likely making things worse.Jan 03, 2011 · Usuallly weak spark cause a misfire under a load,the compression increases when you open the throttle and can snuff out a weak spark --the cap and rotor can cause this even if they look perfect,but spark plug wires that are cracked,burnt from lying on an exhaust manifold or header will do the same,so can plugs that are fouled,or a weak ignition coil or pickup coil,sometimes the ignition module ... The Cheap rehab '79 Chevy truck is running pretty good, but still has a nagging misfire. A recent compression test and plug analysis reveals that the bottom ... no, does not idle at 2000 rpm's idles around 800-1000 when warm, it stumbles sometimes at the 2000 rpm mark, From looking over some other threads I guess the pressure is fine. Some other people have noted that when it hot out pressure drops to 5 psi when at idle, which is what mines does. not sure why it's only at 2000 rpm that the engines ...Good evening. I am new to this forum and have a question. I have a 1995 Maxum SCR 2400 with a Mercuiser 5.7L V8. Had it out on the lake Saturday skiing with no problem for a couple hours. After a short break i tried to pull a skier up and could get no power. The engine would only rev up...Feb 07, 2009 · I have a 79 chevy 3/4 ton pickup with a fresh 350 bored 40 over it has an edelbrock rpm air gap intake, edelbrock 600 cfm carb, headers, accel coil, and cranes power max cam with an advertised duratio … Dec 26, 2009 · I have a 1994 Chevy 350 , upon attempting to accelerate there is a lot of hesitation or sputtering from the motor. Thought it was a dirty carb or water in the gas but thats not it. Was told by a frend that it could be a bad distributor cap and rotor , any comments on this diagnosis ? The truck has 120 K miles on it Answered in 2 minutes by: Jun 10, 2021 · The car/engine (specs are at the end of this post) bogs down under load. Specifically, when I give it gas, the engine initially responds normally, but then bogs down/stumbles. Then, I give it a bit more gas. Again, the engine initially responds normally, but then bogs down. The engine runs fine idling and when I give it gas with the trans in ... Plug the scan tool in the port located under the driver side's dashboard. Follow the instructions on the tool's screen, and wait for any faulty codes to appear. Figure 1. Scan tool port location. Low Fuel Pressure If you don't have a scan tool, you can start by checking the pressure on your fuel system.3,105. Aug 17, 2010. #8. Re: Chevy 350 Engine/Mercruiser 5.7 Problems!! I hope the gauge was wrong and you actually had oil in there. What I think I'd recommend is when you get your boat back from the shop, every time you get it back, do some basic checking on it yourself before you try to go on the water.The car hesitates and stumbles, but give her a little more gas and she takes off. Well, thought it may have been just the old engine. Put a new GM Performance 290 HP 350, GM Performance mechanical fuel pump, MSD distributor and ignition, wires, plugs and a K&N air cleaner. We transferred the new Edelbrock intake and carb to the new engine.Dec 24, 2005 · It is worse when under load. Hei is hooked to ported vacum on the carb. Initial timing is 10-12 Deg Full(total) timing is 22 deg I don't think the Vacum adv is working (New vac mod) Idle is set at about 600-650 RPM ( Guessing!! no tach) Any thought Oh yeh it will fire through the carb. Somtimes when you stomp the pedal in park and want to die. Hesitation is when the engine stumbles, misfire or when you step on the throttle or you accelerate it lacks of power. The issue occurs most generally due the air/fuel mixture is going lean or isn't being enriched properly. Or when the air/fuel mixture going to lean or the engine comes under load, the ignition system is weak and misfiring.1. Excessive Oil Consumption. One of the most common 2007-2013 GMC and Chevy truck problems owners experience is excessive oil consumption. This problem led vehicle buyers to launch a class-action lawsuit against GM, which alleged 2010-2013 vehicles with Generation IV 5.3 Liter V8 Vortec 5300 engines were defective.Aug 21, 2019 · It will start normally and idle fine (with a barely noticeable misfire). It behaves pretty well until it starts to warm up. After warming, the engine starts missing significantly when I give it a little throttle (neutral or in gear). If I keep a light throttle in neutral the miss will get worse until it barely keeps going. 1993 chevy camaro z28 with a drivability problem not setting any codes, it have a stumble and weak power under load conditions problem not present will in closed loop (cold) ... I have an 89 chevy k2500 silverado 4x4, 350 engine, auto trans, ac, ps, pb with 180 thousand miles. It runs great down the road but idles rough.Chevy silverado 5.7 350 hesitates under load!! Fixed 191,945 views Jan 6, 2016 551 Dislike Share Save Jmoney's garage 395 subscribers Chevy silverado 5.7 hesitates under load. This goes for all... Jun 10, 2021 · The car/engine (specs are at the end of this post) bogs down under load. Specifically, when I give it gas, the engine initially responds normally, but then bogs down/stumbles. Then, I give it a bit more gas. Again, the engine initially responds normally, but then bogs down. The engine runs fine idling and when I give it gas with the trans in ... Gauges are $20. Specis 60-66psi at Key On ENgine Off (KOEO) Key On Engine Running will be slightly less. Could be a vacuum leak, take some brake cleaner and spray it around all selaing points of the intake. If the engine idle changes, you have an issue.Chevy small block cylinder misfire/rough acceleration. Am I an idiot? My 1986 Silverado C10 with a small block 305 is having a weird misfire issue. At idle it has a slight miss, and under load any sort of load or while accelerating through mid range RPMs, it runs like absolute crap and will even feel like a shutter at times. It feels like a ...Turns out there are two very common and easily correctable problems with tbi motors. First, the fuel pumps are extremely picky and prone to fail if run out of fuel. Sometimes it is no big thing, sometimes pressure/volume problems arise. Easy to replace, any junkyard with chevy/gmc trucks has a dozen of them.Winging the throttle to 3k in neutral DOES NOT use as much fuel as it would when driving at 3k - a motor UNDER LOAD uses more fuel - your letting off the throttle supports this - since yuo are basically reducing the load and are definitely reducing the amount of AIR which makes your LEAN condition BETTER.Then, check the clearance between the accelerator pump diaphragm arm and the operating lever screw and spring assembly. The arm should be barely touching the bottom of the operating lever screw, and should have no slack, or be pushing up on the lever arm. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom.Aug 12, 2014 · I have a 1968 camaro RS with a 350 I built and have had on the road for about 2 years now. The car used to run like crap, but fixed that issue by increasing the jet size from 65/68 to 69/73. Now the car runs much better, but still has two small problems. The first is a problem at part throttle under very low load (flat ground, 1800-2400 rpm). The Cheap rehab '79 Chevy truck is running pretty good, but still has a nagging misfire. A recent compression test and plug analysis reveals that the bottom ... Back firing. 10-19-2016, 04:16 PM. 1964 Impala sbc 283 .040 over edelbrock thunder avs 500 cfm carb, performer EPS intake, refurbed H.O. 305 heads (I think they are only off 2cc from stock) and 204° / 214° .420" / .442" 112° 107° on the cam with msd 8360 distributor and street fire wires. Vacuum was around 13-14.1) The float level and drop both need to be looked at one is too low to where the force in the jets is insufficient, drop is not enough feed valve opening to keep the fuel level high enough when the throttle is wide open. 2) The main jets are too small. 3) The metering rods are too big. 4) The secondary jets are too small. how to trade on iex exchangexa