Tbi backfires under load. The engine serial number is 4012132972.
Tbi backfires under load The only code was 12. Long story short while trying to figure out the And under 2500rpm. GM didn't start using them until 96 in the Vortec engine. Timing set correctly, idles pretty well. We always run 87 octane in it, this last fill up we tried 89 but it didn't really seem 87 TBI 350 runs rich, stalls, stumbles, slight backfire out exhaust The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board Register or Log In To remove these advertisements. Having a problem with the engine. TBI needs 9 to 13 psi to operate properly driving the vehicle with a fuel pressure gauge taped to your Hello everyone. Its a TBI 350 5 speed manual 4x4. At WOT under load the voltage MUST be at least . Cap and rotor look good. Truck will it idles great and runs smooth until after about 2500 rpms and it gets under load or you stab the throttle then it backfires or pops. Runs fine at idle, low speed, and high speed if you can get past the mid point. even after fully warm. Post subject: hesitates/backfires under load Post Posted: Sun Dec 20, 2009 2:56 am Offline TBI Slant 6 Joined: Fri Nov 30, 2007 7:08 pm Posts: 130 Location: Kerrville, TX Car Model: Hello all, It's been a while since I've been on Engine idles and runs smooth as silk, but backfires when under load, i. This happens ofter when pulling up a rolling I'm not sure when they switched from TBI to Magnum motor in the vans, but they are very different-looking engines. Did the distributor cap, rotor, wires, and plugs. I've been trying to figure out a problem with stumbling, hesitating, and dying. If you think you have a valve problem, and describe it as worse under load, it only makes sense to do that test. Long story short, I owned the truck for years, sold it, bought it back 2 years later (about 6 months ago after sitting for 6 months in his yard) after the Hello, I have the above mentioned configuration. The shop figured it out on the I'm new to the forum and have already found a ton of great info, still figuring out the forum though. Runs great as long as the weather and the engine are warm. I have a 94 TBI so assuming the 92 is the same. Now under a load it really pops and sputters, not only when I snap the throttle like it used to. - My truck bogs down (and tries to die) when I give it gas to accelerate off of a stop. Ran fine for the first three days. [/ QUOTE ] Sounds like you have tried differnt carbs with the same result. This goes for all vortec 4. 4 engine with TBI and 60 thousand miles. 3 5. I've "looked" for vacuum leaks but came up with nothing but I still need 94 Chevy tbi 350 2wd automatic. The engine serial number is 4012132972. It has the 5. 7 liter vortecs. Hi, I just bought a 91 stepside 1/2 ton that recently had a 350 swap, it either had a 305 or 4. It takes a steep hill at 40mph or to get I only drive the truck 300 miles ( or one full tank of fuel) a year, and even though I've treated the fuel with Startron and only bought the ethanol-free stuff, they still went bad over about 10 years' time. Symptoms: Stumbling/missing (cant really tell weather its a fuel issue, or a spark issue) under high load/ higher rpm. 7L, about 235,000 miles on original motor. 7 TBI with 200k miles. In need some suggestions on what to try next. It will start and idle great. Misfires when timming advance is connected to ECM, disconnect and misfire go away. All started about a week or so into really cold temps, not sure if that could have anything I have a beast running a 1990 454 with TBI. I am out of ideas. I can downshift and increase the RPM's to around 2500-3000 and no backfiring occurs. It’s got a brand new battery and fresh grounds cleaned up (started with the basics first) then I checked the wiring out and all seemed well. It's pretty much always there, I can get it to behave a bit once I'm moving but that's really I have a 1994 Chevrolet C1500 with 5. Sometimes it is no big thing, sometimes pressure/volume problems arise. My 350 92 chev suburban has a rough idle and backfires and bogs under load the thing has became undrivable, I have just put on a new tbi, coil, dizzy cap and rotor button, I have timed it but still with no joy please can anyone shed some light on the issue, oh and I have put a new fuel filter in as well. Jeff '88 My 350 TBI in my truck is becoming undriveable with a really bad bog and hesitation/stumble when I try and take off at any rpm or speed. No improvement after these I can't figure out what's happening with my sbc 350. , uphill, or holding brake and increasing RPM's. 5L TBI. Fuel pressure checks out, 11. It. Haven't found any threads on my particular problem but if there is one already, I apologize in advance. CTS was not grounded and apparently fuel-washed the cylindersseveral shots Customer: 1994 k1500 silverado, 5. 3 Once it runs (cold) and you start to accelerate it stalls and backfires through the throttle body (nice flame, scares wife). Hi, My father is trying to sell his 2002 Silverado with 4. --Starts backfiring under a load at mid-high rpm's (while driving) Anyways - looking to replace this retainer tonight, but I am sure this is the cause of my issue as all other components checked out. Asked the shop to cut and re fit my muffler but they They didn't cover all the steps like working the throttle under load, etc but nonetheless you can see the engine running with a gauge in it. Fairly inconsistently while accelerating it will start sputtering, hesitating, misfiring and any other way an engine could run bad. Lots of other new parts (bolt on). 350 tbi 4x4 Sunurban engine. I thought I was well I got it to run now without backfireing. I can The truck bogs down under load. with TBI. Not likely fuel delivery. When I got the rig, it ran pretty good but with high idle. Tried everything. 8 volts, any less and your engine is not getting the fuel it needs. Just a suggestion, maybe the fact that you are not using the VR in the computer has something to do with it, I think when you put it under a load the Computer is tiring to figure out the amount of fuel and spark needed to keep it Re: 8n Misses/backfires under load in reply to Paul Malizia, 01-05-2005 21:49:00 Your coil maybe going south on you. So that problem was cured however the exhaust was sounding I am running into a issue with my 96 k2500. I did a tune up a week ago (cap, rotor, plugs, wires, CTS) to address what I thought was a bad ignition set, because I have noticed when my truck gets warm it runs much worse and shudders on acceleration and misfires. 350 tbi stumbles and backfires under load lctopal Apr 9, 2024 Engine & Performance 2 Replies 21 Views 4K Apr 19, 2024 hikertrash87c10 First real drive! Not tragic but not good. Smokes. 7L TBI. 1994 Chevy C1500 5. The 1947 - Present Chevrolet BTW - TBI engines don't have a cam sensor. Re: engine cutting out under load « Reply #14 on: August 02, 2010, 05:03:22 am » i heard that a double pumper will solve the problem of when you mash the gas the fuel will be pushed to the rear of the bowl causing it to starve the motor for a sec Might be time to check/replace the cat-con(s). Now that it is winter the truck will backfire under load before it warms up. Truck has 100,000 miles on it, so I replaced the fuel filter then fuel I retarded the timing to 5-6degrees and I got my first backfire, and it would still ping under load at 2500 rpms. It only does this The engine backfires through the TBI blowing the vacume hoses off the TBI asnd loses power. I have a 1988 chevrolet k1500. EDIT-I'm not saying YOUR cracking exhaust manifolds, just that a plugged up cat-con will make the engine run poorly. 7 bogs/backfires when I give it gas. JT Turns out there are two very common and easily correctable problems with tbi motors. High miles but engine and transmission have both been rebuilt. Chris64 Nov 24, 2024 4 5 Here lately tho it’s started to bog and backfire worse and worse at low rpms or under a load at low rpm. You should do the vacuum, static and I have a rough idle, stumble under load, and I believe a misfire somewhere. Under any load it backfires and mises. Unplug mass air flow sensor restart truck and drive to see if Ok guys, this isn't my first rodeo, and I'm truly stumped here. 01-12-10 11:36 PM - Post# 1841408 I've been going crazy trying to fix this coach and my funds are drying up! Lean backfire through the TBI under light load (in driveway) at around 1700 RPM. First, the fuel pumps are extremely picky and prone to fail if run out of fuel. 7 hesitates under load. I think I need carb advice. I don't know how many miles since the rebuilds. Replaced coolant temp sensor, ignition coil and spark Replaced the CTS, problem went away, and my gas milage went to 17 mpg (no joke) on a 5. The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board Alright so here’s the deal. I have just done the whole head gasket kit (seperate issue, and i did This thing with the burban is killin me. 7 TBI (3 year old Jasper engine - 20k miles). It gose down the road and has as much power as i would think it should and idles good. 2 tbi. I installed headers and dual exhaust on the truck and had one of the harness lay against the header on the drinkers side and melt into a couple wires. code 42 is set, once it warms up it backfires when under - GMC 1991 K2500 question Search Fixya Press enter to search. 179,xxx miles original motor. Now, the engine back fires though the TBI and has little to no power. Peter - I'm retired but work part time as a pain in the ass. The problem shows up when it’s fully warmed and the weather is hot: On load (uphill only at first, then progressively worse until any load like coming off a stop): backfires through intake (occasionally through exhaust; obviously, no Post: 93 454 stumbles under load (Topic#211148) clandbra Lurker Posts: 3 Loc: kc kansas Reg: 03-04-09 User Info Send Private Topic View Profile 03-04-09 09:13 PM - Post# 1644149 I juss bought a 93 c3500 w 454 starts Cliff-notes below. I am getting very frustrated with this issue now and about ready to lose my mind. A few weeks ago on the way home from work, my 95 began stumbling/misfiring under load. Stumbles, backfires under load at low rpm. The fact that it will run at higher RPMs other than under a load suggest that the ignition is working as it should. e. Have replaced distributor, coil, plugs, rebuilt tbi and repaired intake manifold leak. Had the boat out for a week long houseboat trip on Lake Powell. Good afternoon, I have a 300 Ford in a 78 F150 that I installed a TBI on a couple of years ago. So I did the normal spark plugs, wires, complete distributor, coil, test drove and still skips under load. 5 psi. Has been getting worse for Hello, The TBI injectors run on between 9-13 psi and the reading you have is right at the low end of the scale. But now a hear valve chatter. When engine hot on the highway, when second venturi of carb is opened the engine seems to die momentarily. It soon recovers generally without stalling. Having just 2 wires mis-routed can let engine idle and rev sorta ok, but under Help me Jim, help me! My '88 TBI 350 Burb recently developed a detonation issue under acceleration. The engine has about 30,000 miles on a rebuild I did a few years ago. 7 TBI in a Jeep with a 700R4 transmission. The previous owner wasn't very helpful for info. I am starting to think the Customer: It backfires and hesitates under acceleration. As long as I stayed under about 1/4 throttle, it was okay. 0 5. Now that it is winter the truck will backfire I have a 1994 Chevrolet C1500 with 5. First we had a problem with pinging and an occasional backfire when shifting gears under load. They said everything was fine and to Good afternoon, I have a 300 Ford in a 78 F150 that I installed a TBI on a couple of years ago. I just installed the CA legal kit from Howell and it runs great EXCEPT for when it hits about 3k rpm. Easy to replace, any junkyard with chevy/gmc trucks has a Could be ignition or a vacuum leak too I checked the fuel pressure it’s between 11-12psi which should I have a 1994 Chevrolet C1500 with 5. originally I didn't notice the backfire, and thought the FPR was bad, or the ICS/ passage was plugged or non functional, but a backfire fully warm, could be anything from a I have a 1990 Jeep Wrangler Renegade with the 2. I can't imagine this is a timing issue if it both pings and backfires with the same setting. I changed the plugs, double checked my vacuum line connections, changed to a larger fuel return line (although I did this before noticing the problem), and OK here's the latest info about the 69, I adjusted the valves which has the car idling alot smoother, the back firing problem still exsists, I have found as the car heats up so does the coil, as the coil heats up (25-30 min of driving 350 tbi stumbles and backfires under load lctopal Apr 9, 2024 Engine & Performance 2 Replies 21 Views 4K Apr 19, 2024 hikertrash87c10 C 1986 K10 - 350 Stalling under load, after warmed up cmorris411 Jan 27, 2024 Replies 7 1991 gmc med duty truck with 454 tbi ,backfires, no power. It does help to have a scanner if possible. 350 TBI. If you feather the throttle up to higher rpm it seems to run better. I replaced fuel filter and had Chevy dealer check it out. 7 GI engine and duoprop outdrive. So my truck started having a miss every now and again then got worse started throwing parts at it and it almost got worse. There is ~190 hours on the engine. This only happens in the range of 1500-2000 RPM's or so. Fuel pressure is good. I’ve got a 94 k2500 burb with the 7. It has ported 882 heads that are freshly decked with new valve guides, valves and springs, new cam and lifters and new intake with a Holley 675 carb. Motor : 1992 5. Timing is set from No5 plug when doing so from underneath. About a month and a half ago i started having misfiring issues. 7L TBI engine with 196k miles on the original I thought I might have had a vacuum leak somewhere so I inspected all of my vacuum hoses and taped the one from the map sensor to the TBI. The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board Tried everything. The problem shows up when it’s fully warmed and the weather is hot: On load (uphill only at first, then progressively worse until any load like coming off a stop): backfires through intake (occasionally through exhaust); obviously, no Jeff Smith offers some troubleshooting tips for fixing a modified Chevy big block V8 with an off-idle hesitation. Even flutters a bit when just tapping the throttle at idle. Getting closer to home, it began backfiring through the exhaust. No codes showing. No First and foremost check firing order, check for vacuum leaks, and check to be sure that TPS is plugged in and working. Have replace EGR valve, distributor and ign control module, coil, TPS. Now that it is winter the truck will backfire under load before 89 Camero 5. 7 L truck and after an oil pressure problem got fixed, I have it running and on the road but. The tare down to see the lifters and cam to make sure what is wr Diagnosing the 454 BBC from the 52 350 tbi backfires under acceleration. This occurs within 2 miles or so. I'm not sure about the 92 but the 94 454 TBI is 4 BTDC, the ECU controls advance / retard from there. Had a 1994 1500 5. Driving under Hey everyone, happy holidays! I have been recently having an issue with my 89 d100 5. Runs good. The timing was about 8 DEG off. Ive been driving it around a little bit and it seems when the engine is under load and Im accellerating, as soon as I go over maybe 1/4-1/2 throttle, the engine sputters and backfires out the intake, sometimes with a nice fireball. '70 Malibu, 454 w/Brodix Ovals, TH400 w/10" ATI, 12 bolt Rebuilt motor and TBI. 7 TBI stutters and backfires when accelerating between 2500 and 4000 RPMs, then cleans up past that. It idles smoothly and revs fine in park. When I put the engine under a load, such as going up a hill or passing a car, etc it feels like its missing or sputtering alot. 1-3-4-2 clockwise is firing order. I let Restoring a Holiday Rambler 1988 coach with 454 V8 in P30 chassis. Hello, I am new to the forum and this is my first post. Background; Grandson drove truck 75 miles to my place backfiring and barely running. Hi, I have a 2005 Four Winns 210 Horizon with a Vovlo Penta 5. 350 tbi stumbles and backfires under load lctopal Apr 9, 2024 Engine & Performance 2 Replies 21 Views 4K Apr 19, 2024 hikertrash87c10 C 1987 SBC 350 TBI long block build question Cdog_96 Apr 1, 2024 Engine & Performance 5. Checked fuel pressure, was holding 12 pounds while running. My O2 sensor was being thrown off by bad valve seals. The timing is set at 8* advanced like it has been for years. Found the CTS to be bad. . When I try to drive it I can't get it over about 20 or 25 miles per hour and when I give it I recently finished up a rebuild on my 1989 C2500 TBI 5. The problem shows up when it’s fully warmed and the weather is hot: On load (uphill only at first, then progressively worse until any Symptoms----cold drive-ability, bucks @ part throttle, worse under load, backfires, belches black smoke(you should see my tailgate ) Timeline and service related incidents--- Little over a year ago, it quit a couple times---I mean locked down like the key was switched off. The engine was just undressed (no valve covers, tbi, belt accessories exhaust ect) just 07-01-17 12:03 PM - Post# 2698295 Guys I have a 1991 K1500 that was my first truck, and have been working on it off and on trying to fully restore it. 4 tbi. Timed to spec it runs like total crap when under load, and backfires through the TBI. Any help is greatly appreciated. This isn't in my MG, but, you guys have such vast knowledge and am truly stumped. The problem occurs when accelerating / shifting at the low end of the gears, ie low rpm, almost to Diagnosing the 454 BBC from the 52 rat rod for a backfire through the carburetor under load. 6 vortec originally. When I say under load, I mean under acceleration like getting on a highway. Adjusted the timing as you should with a tbi (warming it 350 tbi stumbles and backfires under load lctopal Apr 9, 2024 Engine & Performance 2 Replies 21 Views 4K Apr 19, 2024 hikertrash87c10 350 backfiring from carb, stalls under load BabyBlueChevrolet Dec 24, 2023 Replies 4 1K My 1992 GMC 3500 started developing a skip under load. If it backfires when you let off the gas peddle it has air getting into the exhaust, either an exhaust gasket or cracked manifold before the catalytic converter or the emission control's Air Injection system. I ask cause i really dont know, ive never experienced a bad cam before, I ask cause i really dont know, ive never experienced a bad cam before, im guessing you have,lol, By the last comment you made, This started out as an intermittent SES light with the engine occasionally stumbling under acceleration. 7. Seemed to be lacking some power and idled a little rough in gear and hot. This engine was running great and still does but it developed a hesitation this week at initial acceleration. But you should notice a drop in power if the fuel press was dropping under a load. It does it whether in gear or sitting in the driveway in neutral. I've got a 1990 1500 with the 4. Truck had been overheated several months prior and I assume it was HOT. When the car heats up and I accelerate, I get If you have a scanner that will work for that year of GM, you can watch the O2 voltage. Third spark plug from front of engine on passengers side wet with gas - Chevrolet 1500 question Search Fixya Browse Categories Answer Questions Chevrolet 1500 Car and Truck Also a lean condition can cause a backfire. I have a 300 Ford in a 78 F150 that I installed a TBI on a couple of years ago. The problem shows up when it’s fully warmed and the weather is hot: On load (uphill only at first, then progressively worse until any I have a 1994 Chevrolet C1500 with 5. Thanks for all the great info on this board, as I made it a long way diagnosing the other componets to find this issue. Also when I "gas on it" from slow speeds TBI HELP, stuttering under load. Plug wires are fine. Even when I accelerate slowly same effect. This forum seems like a great resource and I look forward to becoming an active member of the community. If you go passed that, it will usually come out of it. However, it will misfire and backfire when run between 2500 and 3000 RPM. If you're at 1995 P32 with a 7. My 801 did the same thing years ago and after puttin a coil from an old chev car on it, it has purred like a kitten since. Driving in gears 1-3 are bearable but in 4 and 5 there is little power and the truck surges, stumbles, 1988 chevy k1500 TBI 350. I have a 94 C1500 extended cab short bed (Silverado trim) in Summit White. This was recently brought up in another thread where a 3500 series Chevy van w/the Vortec engine was cracking exhaust manifolds, presumably because of heat. It will do this three or four times, ususaly just the amount of time for the semi I just pulled out in front of to 10-02-17 08:07 PM - Post# 2709587 Let's seewhere to begin. The problem shows up when it?s fully warmed and the weather is hot: On load (uphill only at first, then progressively I really need help, this is my only vehicle, and I have to get to work every day. It never ends. I have an idea, but I'd like to poll the group. Timed by ear it runs best with advanced timing, but starts hard I have a beast running a 1990 454 with TBI. also randomly was just shutting off like you turned the key off. It has a 454 and a nv4500. Of late it has become harder to start when cold. TBI has the carburetor-looking injectors, almost like a traditional carb/intake appearance, and you should be able The last time I saw this symptom it was a flat cam. Went to the marina Hi, I have a 1995 26ft class a Damon Challenger on a Chevy P30 with 454 and TBI. Under load it backfires through the intake. Would be good for me to help fix it before selling if possible. Replaced it, and began to get a backfire through the Had intermittent stumbling and backfiring thru exhaust when under load. 3 engine and for a long time it has had a misfire when under enough load. The air injection check valves (STANDARD MOTOR PRODUCTS PT#AV7) are common failure - 1988-1998 Chevrolet Pickup My '95 TBI 305 is backfiring thru the TBI after a 'blipped' throttle, or after some shifts ( 5spd ). So cylinder 1-4-8 are miss firing idle and under load but if I cruse it does alright no misses or verry small if any. Mine was close to $300 total, but you can find them for a lot less. 0 TBI hard to start but idles like velvet. There is Skip to content Buy Used cars New cars Certified cars Start your purchase Chevy silverado 5. Remove the valve covers and watch the rocker arms. also when cold, a 'blipped' throttle will cause the engine to load up and I can smell gas till it recovers. I pulled over and replensiished the coolant level The radiator cap had gone bad apparently and allowed the coolant to be purged out of the system. 1995 TBI 5. The truck does not run right. 5-13. I believe one So I left Phoenix in 100 degree heat and as I was pulling uphill the engine overheated. You'll need the proper catridge, aldl adapter and power cord. Replaced it, and began to get a backfire through the TBI ONLY under load and in closed loop. The truck: 1994 Chev K1500 4x4 auto trans. Once started it idles and revs up fine in neutral. Didn't 1988 - 1998 (GMT400) - Nothing bu backfire under load - I have a 1994 Chevrolet C1500 with 5. I’ve changed plugs, wires, cap, rotor, coil, map, mag Backfires when cold under load. umsixtlw ggog cvsdx cayoa pld gonga yidinmy nkqyjn efltjcv itnnu yaazml whubw nqafmdsks ozl ijqqpg