1994 Chevy C1500 5.7 bogs/backfires when I give it gas.

I failed to mention that the Check Engine light is NOT on.

I had the same issue.. It was particularly a little worse until I canted my Cam Shaft Position sensor located inside the distributor cap, and also changed the connecter wires to the crankshaft position sensor located at the front bottom of the engine by the fan kinda. It still does it a little but not as bad as it did so I would start there to improve it some.

Same thing here. Did you ever find out what was wrong with it? I've changed/ replaced cap, rotor, wires, plugs, crankshaft position sensor, cam position sensor, MAF, IAT, TPS, coil, fuel filter, oil and filter. nothing seems to work. i've checked for vaccum leak, fuel pressure, fuses, shorts, etc.. Im still fighting this battle so if anyone has any tips I'd greatly appreciate it.

Have you found out the problem with your truck I have a 1994 chevy c1500 5.7, it mostly backfires when driving on the highway or interstate but once it starts it continues to do it with in town driving to. A lot of the time I have to shut it off and start it back up to get it to quit to get it to quit but ithe usually only stops it for a few minutes. I would also greatly appreciate any tips.

My 94 Chevy Silverado was also sputtering, backfiring, missing etc... I changed the fuel filter to no avail, tried several things to get it to run smooth but nothing helped' until a friend of mine who used to have his own shop told me about a memo he had received years ago dealing with this identical problem. here's what worked for me! I unplugged the idle air control from the left side of the carb (as you are facing it) took a large wrench and removed the idle air control from the carb, and sprayed it down with carb cleaner. then I sprayed the fitting on the carb where I removed the idle air control unit from and sprayed that throughly also. then I sprayed the carb itself. once this was done i let it dry for a few minutes, re assembled everything and tried to start my truck. starting the truck was not easy because of the carb cleaner. it took a minute to start, but once it did it ran like new!!! it has been running well ever since. I hope this works for you as well as it did for me.

I have a 1994 chevy 1500 , 5.7 . I took off the transmission to work on the rear main seal . Put the transmission back on and the truck wouldn't start . I than checked the battery got a new one . Than the the starter is new the rotor and cap are new the control madule the iac is new fuel filter in line is new plugs.I can get it to start but only stays running for maybe a minute or two

To the fella that had his friend with memo, by God when i tell u we have had nothing but trouble with this 94 Chevy since we bought it last year for 3200 replaced so many things on it, it's doing same thing it did last year when we got it out, they said we had water in gas that went through the injectors, We replaced I'm n plugs n have drop gas tank n cleaned it out, it's backfiring and carb has flames, We sprayed it and that was result but haven't removed the new icv n sprayed it

thrudel controll value

i have a 1997 chevy 1500 and i have replaced the camshaft sensor and the icm it fires up and back fires then just turns over any ideas would be greatly helpful

Ideal air control valve, or throttle position censor or both. Get a paper clip and bend it until u have 2 points next to each other about 1/8 apart. Turn your key to on position (Don't start it) just on position. Stick the paper clip into your obd1 at the top right two inserts then count the number f times your check engine light blinks. You'll have sets of 2. Like 1 blink then pause then 2 blinks Your obd1 is located under your steering column

Hey guys I was having the exact same problem with my 1998 silverado 5.7 liter. I noticed gas some time ago right where the fuel rails go into the intake,and on the right side of the rails there is a cover with wires under it and they were eaten up by the gas.I had the same symptoms as everyone. Used liquid tape to recover exposed wires just to find out the gas is coming from under the wires. Off to the shop we go.I hope this helps.someone

i dont understand what up with my truck either its a 1994 c 1500 and when i start it it acts like it wants to dye and when i reverse it dyes and then when i try to go it trying to dye and back fires and when i hit the gas it tries to dye and wont go. i have replaced the spark plugs and wires and fuel filter and fuel pump and throttey sensor and still have the proble. the worse time is if its cold or been satting for awhile then it acts up. if anyone can help me find the problem please let me know.

It might that the transmission is going out

I replaced the transmission already

Try a timeing light check the timeing

Holy carp my 94 cheyenne k 1500 5sod 5.7 is doing the exact same thing everyone described but it just started last week. I replace entire fuel pump sending unit few months ago so its new. But just blew clutch fork out last week n pulled tranny n replaced it now I'm having same problems everyone's describing sometimes stslls when idling and 2nd and 393rd hear around 2500-3000 rpm starts dying out and backfires then picks back up. Don't have the $ to just start replacing everything. Just put cap n rotor n still doing it. Going to replace wires n plugs on payday. Any help would b greatly appreciated and can't afford mechanic so I'm doing it myself and need the truck for work.

have a 87 p3500 stepvan everytime i hit a bump going down the highway it tries to stall then sometimes it will pick back up sometimes it won't but when it ttys to stall it often backfires no plugs and wires checked all electric any idea what this could be?

My 1958 Chevy 283 Power Pack has been backfiring, stalling and hesitating at the wrong times. I have been told to rebuild or replace the giant four barrel carb and that will settle it down. It's never been cleaned.

i was going to try to get a new carb but wasn't for sure that could even be a issue everyone kept saying electrical but i found no loose wires or anything at this point its a gamble sinking too much money into a bunch of things that won't fix the problem almost worth getting a new motor

i cant afford a new motor or to a place to have it looked at either. so i guess ill either keep buying parts or just junk it but i need it for work so i don't know what to do. if anyone can help me i would love it but if not ill keep buying parts till i find out whats wrong with it and hope it can take me back and forth to work till i find out whats up.

my truck dose the same but bogs when im driving no at a dead stop and when it bogs it dosnt come back untill my truck is fully turned off for at least 5 min. possible its a fuel filter / pump but not 100 percent

My 1993 5.7L TBI engine would bog down when climbing any small hill and the fuel economy was horrible. I used the symptoms and troubleshooting from the above comments and solved my problem. Thank you very much. Here is my solution. Sorry for the long story, but all is helpful in the long run. I removed my ignition control module and took it up to the orange auto parts store to purchase a new one, but the helpful parts person told me, before I purchase a new one, to go to another orange store and have it tested since they misplaced their instruction manual for their module tester. Instead, I went to the green auto parts store across the street and had the module tested. The two counter persons were not properly trained on how to properly operate their module tester but hooked it up from their instruction manual "without grounding it" and my module repeatedly failed all of the tests. I went back to the orange store to again purchase a new ignition control module but a different counter person found their instruction manual and tested it "while grounding the case." The module repeatedly passes all tests. I then recognized the differences in the grounding and then recognized small burn traces on the back if the module where it had appeared to be arching. I then suspected that the module was not properly grounded in my vehicle since the hold down screws were very rusty and the heat sink grease was gone between the two metal surfaces. I purchases some new heat sink grease at Radio Shack and went home. I uses a small wire brush to clean off the rusted screws and mounting surfaces. Applied new heat sink grease and reinstalled. Wiggle the module back and forth for a minute to properly distribute the heat sink grease. I backed off the screws several times to get the serrated screw washers to make a good grounding bond and put the cap back together. All of my engine bogging issues are gone. I can now rocket up a hill. Lessons learned: 1) Make sure the parts service persons are competent in their job. 2) Radio Shack has heat sink grease when the auto parts stores do not. 3) Make sure the ignition control module mounting screws are free of rust and the module is properly grounded. 4) Wear latex gloves when handling heat sink grease. It is contagious like a disease and gets everywhere you lease expect it.

Hey guys I have been having the same surging issue from dead stop for months.. I just allow for the slow acceleration time as the truck is old and mechanics are expensive.. But the last week I was traveling and the truck just shut off no burp chug or chatter.. Just went to give it has and nothing there.. So after trying to trailer it home unfortunately my winch wasn't strong enough to pull the truck up.. I replaced the ICM on the side of the road and it fired right up.. But I still have the surging/backfire from dead stop. Any other suggestions? I'm purity sure I have a throttle body and 2 injectors.. Would the idle sensor still be present?

I have a 98 1500 4x4 5.7 vortex. Was able to start with a little starting fluid to move around but now no start. It has new fuel pump. When it was starting it would not want to go when I gave it gas, unless I barley press the gas. Never backfired. Please help!! Wrecked my car so now need this as a daily.

I have a 1993 Suburban K2500 with a 454 c.i.d. that has a rough idle, and will bog down on acceleration. When I'm at freeway speeds, it will surge and backfire. I have tried all the fixes above including; TPS, MAP, IAC, O2, fuel filter, cap, rotor, plugs, wires, throttle body base gasket, computer, promand the list goes on and on. I have replaced the distributor about 3 months before this problem reared it's ugly head. I have re- grounded the entire engine with several new ground straps and replaced wiring to the knock sensor, the O2 sensor, and the coolant temp sensor due to age and oil contamination. I have also replaced both positive and negative cables and ran a new ground to the PCM. Any thoughts???

My 96 c2500, 350 tbi, has been spuddering, idling really rough, backfiring, amd plain out dying in town. Sounds like plugs but its not, distributor maybe? Timing? No engine light either So i was just tinkering with the truck, and the wire under the the glove compartment, its brown and black, (you disconnect it before you do set the cap for your timing) i unplugged it and the engine light came on, but the truck instantly started working way better. It dont make much sense to me and i am not sure if its really safe to run that way. It seams like it might be smoking a little maybe? Any thoughts or ideas?

most of the folks here with these problems mention a transmission replacement, you have a constant hot wire that runs down and around the stock exhaust manifold and through a heat shield and back to firewall. I also swapped tranny out of mine, (for another truck) and then back in (to drive this truck again) and forgot to bolt the heat shield back via the bell housing bolts. This allowed the always hot wire to ground out on the exhaust and the truck would sometimes die, always backfire, and it usually happened when I hit a bump. I disconnected the wire, pulled it through, taped the exposed wire, ran it along the inner fenderwell and up by the ac drier and back to it's original location without getting anywhere close to the exhaust. Also, there are other backfiring issues, that sound like this is not the problem... these trucks' have distributor issues, a new distributor will likely fix your problem. A coolant temp sensor will make you run rich, the pigtail wiring harness always gets internally broken on these due to the way the engine rocks under load, try to wiggle yours while running to see if the problem fixes... also the TBI injectors have their wires running through a rubber gromet and that over time can wear out and the wire grounds to the air cleaner assembly. if you gun it and it picks up then immediately loses power and check engine light comes on it's your knock sensor most likely, or the connector is loose. and one very important thing to remember, if anything is not properly grounded, or not getting proper power, it will not work, and when sensors don't work on a computerized engine you will have big problems!

bogey, if it's smoking black it's running rich, you'll foul out your plugs running it like that, the knock sensor and electronic spark control module are responsible for adjusting your timing. the ESC module sits under the air intake side of the air cleaner and you should check the wires running to it, wiggle test, and also check that there are no vacuum leaks there and that the vac line is hooked up. your knock sensor is on the bottom of the block, cut your wheel all the way to the left and look behind the plastic fenderskirt. give the knock sensor a wiggle test too. now assuming these two are working properly, the distributor takes the signal, and adjusts timing accordingly, these trucks are known to have distributor issues after 150k or so autozone has them for around 60-70 stock replacement, you'll then disconnect the wire you mentioned to adjust your timing to get the Base timing for your engine. Also, you didn't mention if it did, but an exhaust manifold leak, or noisy lifters even could trigger the knock sensor to retard timing prematurely. have seen guys use knock sensors from 454 to cure this problem because they have a higher tolerance for noise before retarding

try mass air flow with all your back fireing and sputtering

i had this problem also and replaced most of my sensors, with further research i found fuel pump has a strainer at its inlets without hesitation i dropped fuel tank and removed pump. i discovered the sock was covered in debris, went to local autozone and purchased one for 4bucks. replaced it and reinstalled tank. the truck would start and idle fine just under loan it would bogg and try to kill its self. after replacing strainer i lightly accelerated and noticed the truck has sensitive acceleration response. after replacing all sensors and finding problem my 1989 Chevy Suburban (350-TBI-5.7) runs like its right off the lot!!!

I have a 1992 Chevy Silverado extended cab 4 wheel drive automaticit'll pick up gas then just bog down cant give no gass or it dies can some tell what it is bec I spent over $1009 allredy

I could give you a long list of things to check, but you could get a better answer by listing things you've already done. Air/Fuel/Spark that's all you need for an engine to run. check your air filter for restrictions, check your coil, check your fuel pressure. could be a timing issue, fuel issue, cat converter, etc.. If you could be more specific it'll likely be easier to pinpoint your problem.

I rebiuld my pick up chevy s10 to race and its doint that to it bog out and dies i tryed looking for a mecanic but they say its a spark plug but its bran new i tryed to race a corvette with it and the motor. Is so strong that when it bog out and i try to accelarate it dosent accelarate but with that motor the way its acting now i broke to transmission and i beed help finding that problem to but there aint nody out there that know i have a race in like a month from nowto race a camarro but it keep bogging out help me as soon as posible

I've had all these same problems with my 92 Chevy 1500 and replaced fuel pump, filter, egr vaulve, distributer cap and roter, the coil wire and coil itself. Didn't do nothing. Then I found out one of my injectors weren't spraying so I was only running on 4 cylinders. So I rebuilt it and it was running like a champ for a good month and now it's doing it again. But only when my trucks been running for a while. Give it gas it sputters and kinda back fires. But when I get up to speed it runs fine until I accelerate.

my 1996 chevy c1500 is doing the same thing. mine sputters when i try to accelerate then it decides that it wants to go after about 5-10 seconds of sitting there sputtering and backfiring. The engine only has 85000 miles on it. it is a 5.7 liter 350 vortec. it already has a new maf sensor that i installed about 6 months ago. Ive checked all the wires, still have to check all fuses though

i had all of those problems its the throttle sensor on the outside of the air intake opposite to where the throttle cable connects. or i just floor it and over time the problem went away

i have a 93 c3500 with a 350 tbi

The only guy who fixed the problem emptied the tank. I think it is water in the fuel. Under a load at slow speeds the water and fuel is burned in the cylinder creating a backfire, as the steam expands. The stall is from an incomplete fire because the water put it out. Since these vehicles were born before e85 fuel, adding ethyl alcohol could cause the rubber/plastic fuel lines to corrode and fail so be careful when adding additives. best advice take it to a professional and have the tank dropped.

There is a transmission module located on the passenger side of the transmission. This module opens and closed via a vacuum line. it is in the shape of a curve or an "S". You will need a cutter to cut thru original clamps. Make sure you see this rubber hose. Replace the hose that is where you will have a vacuum leak. Replace hose with new one and don't forget to buy two new clamps. This should resolve your issue of sluggish running backfire. I recommend you all try this first. IT take all of about 15 minutes to replace once you have all the items ready to reinstall.

I have 96 chevy 1500 with 4.3 manual trans and I have changed distributor cap/button/wires/plugs camshaft sensor coil and little black box on coil and truck idles great but when giving it has or cruising at 1500 and up its backfiring and sputtering and now my gas gauge is acting weird does anybody know what's going on

I agree!

Me too except my service engine soon blinks fast when I'm driving it. I have changed the rotar, cap, spark plugs, and fuel filter but it seems to run better on a dry sunny day than a cold or rainy day. Any suggestions

I have a 1994 chevy 350 5.7, back a few months ago I was going up hill and started to stall so I floored it and then I had engine ping got back home moved my timing little back the pickup ran awesome til now. There's no engine ping, it starts up fine, but soon as it warms up it starts to choke out at a idle sputters and backfires above 2500 rpms, just replaced the IACV it had no good affect. Cap, rotor, plugs, wires all have about few thousand miles on them also the egr valve, map sensor where also replaced. I got good fuel pressure, new fuel filter and now I'm trying to figure out what is this time. Any ideas are solutions will be very helpful

also there's no service engine light

okay figured it out bad distributor replaced it with a new runs like a champ now I hope this helps someone

!992 Chevrolet 5.7l Backing firing thru tbi,poor millage,hesitation on acceleration. Found throttle position sensor intermittent contact.replaced runs great now.

I have a 94 k1 500 with 5.7 350 I have replaced pump filter distributor plugs wires cap button iac ips map tps computer pcm throttle body tps egr valve hose sensor that goes to egr don't know what it's called o2 sensor and it runs fine in park but when in gear only sluggish when giving a lot of gas on take off or when I'm in a high gear at low speed pops through tbi I'm lost never done so much to truck and not fixed

I am having the same issues but the check engine light is on. Rotor, cap, wires, and plugs have been replace. Rebuilt the TBI cleaned the IACV and the TPS. Still doing the same thing. If anybody has anything new that would be much appreciated! thanks for the advice.

My 95 c2500 was doing the same thing. Id tried new fuel filter checked all plugs and wires. Then someone told me the map sesner could be bad and be forcing the injectors to dump fuel. So far its worked. Also cleaned my throttle body and aired out all gas in the throttle body. Check to make sure its not flooded and your injectors arent bad. Lots of digging but it seems nobody has the answer to this problem

98 Chevy C Series Auto with 4.3 L. Following this thread. So far I've changed wires, plugs, fuel filter, air filter, oil filter, oil, fuel pump, spider injector and all poppets, catalytic converter, cleaned muffler. I see that distributor is a possible problem, may change that. I also noted the sensors (Throttle, IAC, Map, etc.) I will post a solution if I find it. May God help me find it. I have 3 days then I must be on a job with it. If you read this and it stands out taking in account what I have already changed, then let me know. Thanks.

I just bought a 94 K1500 (133k) with these driveability problems. Would really bog down, esp when cold and trying to go uphill... but felt weak under any acceleration. Previous owner did new distributor, MAP, plugs, IAC... still ran like crap! I repl'd temp sensor. The game changer was the EGR solenoid, hardly visible, rarely mentioned. Immediately started, had power on takeoff. ACDelco part, $25 2 day delivery via Am-Prime.

Bro, I feel ya. '94 K1500 Suburban with 360K mi. Been doing well with normal "old age" issues: trans rebuild, cooling system, charging system, and then the shudders happened. The engine starts and idles with no problem. At about 1500 - 1700 rpm under power, the engine bounces like crazy. I add more gas and as I reach 75 mph the engine miss is bearable. After work I ready for the 1.5 hr commute home- the engine runs smoothly until I hit 45 mph and then the bronco ride starts anew. The check engine light is sometimes on and sometimes off. The code is 32- EGR valve I understand. So far I have replaced the EGR valve, EGR control switch, TPS, Dist cap & rotor, and zip-tied vacuum fittings. I will keep you updated

Jack, How long have you had your K1500? Good that you accept that some work is expected on an old truck... but the frustration is understood. I was too optimistic. The EGR solenoid was not the end of my trouble, but it helped. I replaced O2 sensor and fuel filter, but get a code-44 (lean exhaust). I tested fuel evap canister and purge valve, but they were OK. Been doing "Techron therapy" (the weak formula), but am thinking/hoping that injectors might be the issue. They're a relatively cheap fix. I sure read a lot about fuel pump, pressure issues, dirty sock filter, and replacing 42 gal tank... don't like the sound of any of that. You can compare the color of two plugs on opposite sides of the engine (#3 vs #4), if different, may indicate a bad injector on one side, thus causing roughness, etc. That is actually good news... better than doing anything else to the fuel system! A low end shudder, hesitation, etc. is unfortunate, because a truck engine runs mostly at low rpm.

The IAC was mentioned earlier. I pulled it and cleaned it. Idle a little high at first then it settled to around 200. Overall, no change.

I bought my burb new in 94. It has been through 4 kids and all of their swim meets, ski trips, cross country races, tennis tournaments, basketball and softball games, campouts, trips to the city and to the mountains. It's been a workhorse and now it's my adventure race, golf outing, backcountry fishing, backpacking, and just plain get outa town rig and I want to keep her going. I am thinking of a new crate 350. It's going to cost about $6K. I know that I will never get that back if I sell, but who's looking to sell.

Wow. So you REALLY know its history! Sounds like a life well-lived! The truck also :) My '94 Sub was owned by a guy for 18 yrs, but he had so many vehicles, I doubt if mine was maintained in detail. You would know, then, how old your injectors are. These TBI 350s are very sensitive to vacuum leaks... which can show up in weird places, including intake manifold, base of TBI, etc, not just old hoses. Also, there is much discussion about fuel pressure (at various points), wimpy fuel pumps, and dirty fuel tanks. A new crate engine sounds great, BUT, you'd be in awfully deep if tranny, diffs, etc, started acting up. There is some good diagnostic advice @ tbichips.com and also some info on these motors, if you are going to replace it. Ours are not as upgradeable as some other years. Our valves and exhaust are also pretty limiting. It'd be useful for you to know what your compression #'s are, as far as decision making... Good luck and continued adventures.

OBD1 chevy 5.7 TBI - This issue you all have with the backfire through the carb when accelerating from stop.One thing you have to do is very all emission control sensors are operating correctly. Buying a new one without verification is just a waste. If you don't know how to test, Take it to a mechanic. Unfortunately a lot of the old school mechanics just don't understand the electronics. If everyone agrees that the main cause is a lean fuel condition then you need to look at all the scenarios that cause that condition. Here is my list: 1) Weak fuel pump clogged filter anything that hampers the delivery of fuel. This one is easy to eliminate, If the engine runs perfect before going into closed loop it's not the fuel delivery. 2) Problem starts after it goes into closed loop. Things to do, a) Check voltage at fuel pump and compare to battery voltage. The ECM compensates a low battery voltage by increasing fuel flow. If the battery voltage is good but there is low voltage at the fuel pump then it may be causing your lean condition. Check and clean all your grounds. Those cheesy connectors from the factory loose their conductive properties. When they get hot the resistance goes up naturally, but bad connectors will throw a large resistance in the circuit that screws with the electronics. 3) Your engine is worn out, valves not seating compression is low, etc. Compression and leakdown test will help pinpointing that problem. 4)Advance the timing 10 to 12 degrees, see how it runs. If it runs great the the problem is not fuel delivery per say but it probably can be seen in the fuel trim numbers. The 2500 series snap-on scanners are a good tool for this stuff. 5)Also, vacuum leaks can cause this issue, with the scanner your long term fuel trim decreases rapidly, as it does the engine runs leaner and leaner. Really bad because detonation (pinging ) will crack your compression rings in short time. Don't think you DONT have a vacuum leak with a vacuum gauge. ECM will compensate by advancing the timing so it idles with very little problem. Remember the problem occurs under heavy load. Some intake leaks can be difficult to find. If your engine has ever overheated, 9 out of 10 times you will find the TBI / Intake leaks around the base of TBI. Around the TBI mounting bolts. The port and head planes are no longer in sync. I made a plate that bolted to the intake manifold where the TBI mounts. Remove the valve covers and loosened all the intake valve rocker arms. Oh I forgot to mention I threaded a fitting with a schrader valve in the plate so that I could pressurize the intake. Basically a reverse leak down test. The leaks were around the intake where the TBI sits. Mill the mounting plane to make it true, no leaks. 4) O2 sensor slow or off just enough to cause ECM to trim fuel back. 5) The first generation, OBD1 vehicles as simple as they are, are very difficult to maintain in proper running condition. OBD2 is more forgiving with much less mystery. Pulling codes and buying parts is what they want you to do. Don't fall into the trap. Most of the problems with my 94 chevy was sensor wiring. Of course it took a long time to find the backfire problem. Constant lean condition causes the compression chamber to operate at extreme temperatures. Wore the rings out by 150000. Just finished a complete overhaul, it was on the bucket list, rings haven't seated completely with 75 miles on the engine but I can tell that things are lookin up. If it wasn't for the custom work I did previously I probably would have sold it to the wreaking yard years ago. Good luck

So I took the burb on a road trip up into the mountains. First, I replaced the ICM. One more thing to check off of the list. I did not notice much of any improvement in performance. Another thing that was not mentioned is that connections become very brittle with age. I destroyed the connector for the ICM to the distributor pick-up module. Something more to replace. Anyway, as I was decending a very long (5 mile) steep stretch of road I dropped the transmission into 2nd gear in order to save my brakes. The engine did a very good job holding my speed down and it did not backfire at all. Might this be an indication that there are no issues with the valves? That was 300 miles ago. The baffles in the muffler had begun to rattle about before the trip, so I replaced it last weekend. Now the truck is a bit quieter, but it still stutters at low rpms under power. I am still getting the 32 OBD1 code. While I am pondering my next move, I will do a break job.

How's it going fellas It appears that everyone has attempted to fix their 1988- 1999 Chevy Silverado Makes complete sense with several answers. I too have the same problem with my 1994 Chevy Silverado 350 5.7. My Truck ran as if it was like a new truck, It passed the California State Smog Test but for the last several months when I accelerate my Truck if begins to badly bog, But there's one common problem that no one has checked. EGR, You need to check too see if the passive line is clogged with carbon, if it's clogged it will more likely cause the Truck to bog. Another words, the EGR operates the same as vaccum, if its clogged it won't function. I'll work on my truck 9/16/2017 will keep you posted. I may take pictures to show you a clogged passive line / channel. Thanks Dennis California

Did you find out anything on your problem with Chevy motor, mine doing exact same thing, turn it off then on real quick and runs fins fine for a few minutes or so. Sometimes drives ok....ughhh. new fuel pump and filter.

I have 1994 Silverado USA show truck 350 TBI, 172,000 miles. Fought the missing backfire issue for a year, ran smooth while warm up, then miss and bog when accelerating. Long story short found the short vacuum line coming out of the throttle body was dry rotted. I replaced this 25 cent hose, changed plugs and she runs like a top. Hope this will help anybody else with this issue.

I recently solved a similar problem with my vehicle. I thought I would share my experiences in case it might be helpful to anyone else. For me, it was a 10¢ hose clamp. Well…, to be honest, these days it would probably amount to a $1.20 hose clamp. I was having some of the same problems of which many have described in this thread. I was losing power going up big hills and having issues on cold starts upon engaging the vehicle into motion or coasting to a stop while cold (sometimes it would stall out, even at fast idle, as I recall). Those mostly were the only times that I seemed to have these issues, for the most part – except for some occasional ‘lurching’ of sorts when starting from a dead stop. But I was not getting any error warnings/messages (’95, OBD I, 5.0L, 5 speed, K1500). And other than these intermittent problems, the vehicle seemed to run great, as usual. I decided to go ahead and replace my fuel pump and strainer. I came to this decision mostly because someone posted (somewhere earlier) saying it was their fuel strainer causing the problems. Upon removing the installed pump, we noticed that the outlet hose from the pump was not tightly clamped in place (the hose clamp had come loose). We figured the loose outlet hose was robbing vehicle power by leaking fuel back into the fuel tank when the pump increased output pressure to meet any increased engine load (or however the fuel pressure/power gradient actually works in these vehicles, the loose hose on the pump was not copacetic). I know of no reason why the hose clamp failed, for whatever it’s worth. I remember replacing the original fuel pump somewhere between 300k miles and 400k miles (about 10+ years ago). The local discount parts store mechanics were amazed that I never had to replace the pump to that point, with so many miles on the vehicle. I replaced the original fuel pump with an OEM replacement pump that I bought at a Chevy dealer. And I’m fairly sure that upon installing that pump, we used the replacement hose clamps that came with that replacement pump. The replacement hose clamps were of a plastic serrated tooth type of clamp that one just pushes/pinches together and it locks into place to hold the hose to the outlet tubing of the pump (as opposed to a typical metal type clamp with a screw to tighten the metal band). Despite finding the loose hose clamp on the outlet hose of the pump, we went ahead and replaced the fuel pump, anyhow (as the first replacement pump also had about 300k miles on it to this point in time). The hose clamps that came with this second OEM pump were of the typical metal type with a screw – suggesting that the OEM knew the plastic hose clamps caused problems after a while, we figured as much anyhow. I have not had any vehicle problems since – at least nothing significant that I have noticed. It was relatively difficult to diagnose the exact cause of my problem(s), for sure. This was made somewhat more difficult since mine is a ’95 and there is no test connection to measure fuel pressure – though with the proper fittings, one could probably easily measure the fuel pressure at the inlet/outlet of the fuel filter on the frame rail, I suppose would be the easiest place to do so (rather than at the input to the throttle body as most books suggest). But we didn’t bother to look for those fittings to test fuel pressure at the fuel filter. Because we had already decided to replace the pump; as I said, mostly motivated by replacing the strainer – as the fuel filter had a lot of nasty deposits and dirty fuel when we had replaced it during earlier troubleshooting. So, I would suggest, don’t throw away your vehicle because of any hose clamp – if your problem turns out to be similar to mine, anyhow. If one is not able to replace the pump oneself, a lesser-priced mechanic should be relatively happy to replace your fuel pump for $200 or less in labor costs. Just to be clear, initially I did a tune-up (plugs, wires, compression check, checked timing, inspected electrical connections), replaced the fuel filter and air filter, looked for vacuum leaks (new PVC valve, EGR valve not too old but certainly not stuck open), and then I replaced some easily replaceable sensors (IACV, TPS). I replaced the sensors mostly because I was not sure my replacement computer was properly showing error messages (IACV gives no error message, TPS should show an error message, according to the repair books). Though a few days before we replaced the pump, I got an error message of “lean exhaust,” upon driving down the freeway/highway/interstate. So that gave me more confidence that the pump was causing the problem(s). I notice that many who post in these threads never return to tell what resolved their problem. So, I decided I would wait until I uncovered the apparent solution until I posted. Again, it appears the source of the problem with my vehicle was the silly plastic hose clamp on the output hose of the fuel pump – at least it seems to have been the culprit with my vehicle. 620K+ miles and still counting! (I am the original and only owner of the vehicle.) Should anyone be interested, more of my experiences with my vehicle can be read on one of my blogs, located at: http://theultimateroadtripamericac2c.blogspot.com/2017/01/the-600000-mile-intake-manifold-gasket.html AVT

Mine was just the Throttle Position Sensor! I couldn't get a straight confirmation that it wasn't something else, but for $38 I was willing to gamble. With the right tools, which I have, it was a 5 minute job.

IM THINKING IT IS A CHEVY PROBLEM CAUSE IM HAVING THE SAME DOG GONE PROBLEM LOL

Solved my problem and now I feel like racing I have so much power! After months of that “dragging a trailer” feeling, PROBLEM SOLVED. It was my in tank fuel pump. It had pressure, but no volume. Had a local shop drop the tank and change it and I’m better than new!

I took mine to the shop they had to change the fuel pump and injectors and fuel pressure regulator and that fixed it

Had a very similar problem with my 1994 gmc k1500 with a 5.7 I replaced the fuel pump and it ran perfect.

Anyone wanting to sell or close to Grenada Ms

Did you ever find the problem. I have a 91 Chevy truck with a 5.7L doing the same thing. Runs good but when you step on the throttle to get up and go it starts jerking and back fireing from the throttle body. When coming up to traffic lights I have to put in nuetral and keep giving it gas or it will die but will start back up doing the same thing. One day it died on me but when I restarted it and punched the throttle my truck peeled out and had all the power in the world like it was never messing up the 2 seconds prior lol please help

Check your timing. It’s probably slipping. I fixed the problem and added another set of plugs wires an cap and she’s running like a champ.

Had a similar problem with my 1995 Silverado, 5.7L MFI. Replaced the fuel pump, pressure regulator, filter, tested fuel pressure. Problem went away after each repair but returned quickly. Ended up being the ignition module. I pulled the module and took it to O'Reilly auto parts. They put it on the ignition module tester and it was bad. No more problems after installing new module.

Just got a 94 that originally had a 5.7 l he put the 305 in it it was doing the same thing bogging down whenever I try and go from a light or a stop sign but if I was cruising it was fine and park it's fine so I read this forum started changing all the parts everyone's talking about and my end result after changing all these parts was to simply just unplug the idle air control and it runs just fine

I was experiencing the same type off problems with my 93 c1500. Simple answer is that one of the distributor cap screws was stripped so when I pressed on gas it was lost contact and it would stumble. Replaced screw with a bigger one and it runs fine now

I had 2000 had bunch firing problem it turned out the AC hose runs right across the distributor cap an was leaking on it till start miss firing

I have 94 GMC 1500 4x4 with the 350 and mine boggs down when you try to accelerate. Got two answers from a mechanic. One the eag valve might have too much carbon build up.and two the timing chain might have jumped a tooth.I'll try and update after I work on it.

Have you tried changing your map sensor

And I had the same problem I took out the throttle body and rebuilt it now it's running fine new injectors everything

I have 1996 Chevy C1500 4.3 vortec and was bogging out when accelerate on the gas while driving and also lost of power. I had replace a ton of sensors on it and finally I stumbled upon a sensor called fuel pressure regulator right inside attached to the fuel injector spider once I replaced it my truck was finally not bogging out and full power restored.

I have a 1994 Chevy van G20 4.3l. I had timing done and she worked great for about a week. When I take it on the highway and hit 65-70 she starts backfiring and I have to let off the gas and get off the highway. Anyone know what it could be?

CHECK YOUR GROUND! Ours was doing the same thing boggled down real bad while going up hill, died while idle or at a stop. Changed several items and kept messing up. Checked our ground and the thick ground wire going to the wires and computer, passenger side of the motor back side, was loose and corroded. Changed it and reinstalled it and problem solved! No more dying, no more boggling down, and it takes off beautifully while going up hill! CHECK YOUR GROUND!

It's the coil inside your disturbtor replace your whole disturbtor shaft carquest carries it for 150 dollars complete unit I did mine and solved all my issues it's about 2 hrs labour if you want I charge 200 to do the job my number is 6473095653 or newmannewfie@hotmail.com

To most of you guys/ladies with the bogging down and backfiring. Have yall tried changing fuel pump? I have a 94 silverado 350 5.7 and i had the exact same problem for awhile. After changing my fuel pump 3 times its finalky running right again. Make sure you have an electric fuel pump and that its goid. Remember to change filter with it

I had a problem that sounds like this kinda and it was the tempature sensor at the thermostat, those thermostat senors have 2 circiuts in them 1 to send the tempature to the gauge on the dash and the other sensor tell the computer to mix the fuel for a rich or lean mixture for cold or hot weather which can flood the engine at low idle or restrict the fuel. i was having a problem with mine starting fine and as it warmed up it wouldn't turn down the fuel mixture for a hoter running engine and at low idle it would flood the engine unless i held the gas peddle to the floor to use that excess fuel. Ithis system is like having a choke that is being held closed for a cold engine but the endine is hot and need less fuel to run at lower idle speed.

Just to close the loop on my engine issue; I put a new (not rebuilt) engine in her. I used a friend’s shop and was able to keep the cost under $5000. I replaced the distributor and put a larger radiator in. Smog checked (CA) after two years and easily passed. Runs like a champ!