Tbi cuts out under load However, when i’d set it to 4* btdc, the computer would advance it to about 10-12* btdc and i’d still have a misfire. It will correct itself after about 5 seconds, can usually correct it a little quicker by revving. Mechanic's Assistant: Is the power loss consistent, or does it vary? Feb 20, 2009 · Anyway any suggestions would be great, I am hopeing that this only happening under load can rule so things out but then again a TBI 4. Starts bucking like a horse til I let off the throttle for a bit. You may also notice common signs of lean running such as overheating and a hanging idle. It runs well for a minute or so, then cuts out entirely. 7L TBI Symptoms: Rough idle when warm/hot, occasional stall. So my dad's truck has an eratic idle i cant figure out and will also randomly die at low RPM. Oct 10, 2017 · Can't seem to find a correct answer from questions asked by others, so here I am making another discussion about the infamous skip, sputter, stall, rough idle, dies out problem with the 5. The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board Aug 22, 2019 · I also have another 5. Tested fuel pump. On hard acceleration it is bogging down like there is to much air, because sometimes it backfires. 3 is new to me. Solution Vacuum leaks May 8, 2017 · Truck: 1992 K1500 Silverado 5. As long as I stayed under about 1/4 throttle, it was okay. b. I have checked the PCM grounds and circuit resistances, and everything seems fine. It can be done at the supply line at the throttle body. 114,000 miles Truck is mostly stock, summit 1102 cam edelbrock intake headers no cats The truck bogs down and stumbles like it's fuel starved. replaced computer and coil and checked the timing and still same issue. 5 tires and a 350 t. It will start ok and run fine at low rpms but then start sputtering and popping at higher rpm. Some other symptoms to look out for to ensure that the problem is indeed a vacuum leak are hissing sound from the engine bay, stalling while stopping, etc. I thought it was because of an exhaust leak so I tried to repair it but broke stud. It also Mar 8, 2017 · Theres a solenoid to inhibit operation when the engine is cold, but once it reaches around 140-160 degrees, the ECM turns the EGR solenoid on when the engine is under a steady load situation, and if the throttle is open far enough, vacuum is sent directly to them to go full open through a metered orifice. It's a 89 k1500 5. Leaking Vacuum Lines A vacuum leak results in supplying the wrong air/fuel ratio into the engine, thus, resulting in bogging or rough and slow acceleration. 4 L TBI that has had an issue since I bought it a little over a year ago. It seems to be getting worse. MUCH better pump than the EP386 TBI pump. Apr 9, 2024 · I have a 87 Chevy 350 that was running good but latley it has been stumbling and backfiring when you step on the throttle heavy. Only seems to do it at heavy throttle going uphill. Being a TBI,i can clearly see the passenger side injector completely cutting out and starting back to inject when i pull back the throttle. At slow speeds and under load the oil pressure drops to 5ish and stalls out. Model specific subject matter experts, classified ads and more. When installing I found out the firing order was backwards. any Apr 9, 2010 · The next day it was idling and just cut out, it started doing that consistently after idling for more than 3 or 4 minutes once it was in closed loop. 7 TBI stalling out when put into drive or reverse gear as well as stalling at idle and or sever hesitation with RPM's dropping. It has been going on from the first time I drove it after the Sep 15, 2017 · Hi I have a 1991 chevy Silverado that just started about a week or 2 ago misfiring randomly and cutting out under load. (This occurs without any stumble, miss, or other forewarning. Also stumbles a May 20, 2010 · Cliff-notes below. You can do it yourself in under an hour, and it costs around $50. Any ideas? I suspect the 88-95 OBS Chevy TBI Bogging Under Load and Dying At Stops Intermittently The Hands On Channel 31. 1988 chevy 1500 350 tbi bogs down with acceleration or under load and hills Mechanic's Assistant chat Customer: I have a 1988 Chevy 1500 with a 350 TBI, and it struggles with acceleration, especially when under load or going uphill. 7L, about 235,000 miles on original motor. Hey guys! Boat run great for 4-5 passes through the course then bog around 1600-1800 rpm. icio. The system is running lean, and after about 20-30 seconds of being lean, it goes into open loop indefinitely. That did not help either. This is a follow-up video to my question about the GM 5. I took the injectors off and cleaned the assembly, however you can't really clean the injectors, can you? I have yet to test for vacuum leak, but it did run better after I replaced the vacuum lines. Oct 26, 2018 · Cleaned it out in 5 minutes, more than glad that I did. Feb 3, 2019 · 7. Author Topic: 89 TBI 350 Rough Surging Idle, Cutting Out/Stumbling on Acceleration (Read 6678 times) Dr_Snooz Junior Member Posts: 684 "I like to take hammers, and just break stuff" Customer: I have a 1993 Chevy K1500 with a 5. Sep 26, 2011 · Anyone really familiar with the older GM TBI fuel injection? I'm working on an '89 with 350 and TH400. It's pretty self explanatory, let me know if you need any Aug 27, 2004 · TBI Cuts Out Under Throttle Engine & DrivetrainBookmarks Digg del. Feb 17, 2020 · 1991 K5 TBI 350 with SM465. Mar 22, 2021 · My 1995 Chevy 350 stumbles when I take off from a stop. Didn't Mar 15, 2015 · The way the old tbi systems work ( I believe) is anything ported above the closed throttle plates doesn't receive engine vacuum until the throttle is cracked, so a component ported above the plates could leak vacuum and not affect anything until you accelerate. Its most commonly caused by either a faulty fuel pump, or a split or blocked in-tank fuel filter. The result was my Jeep couldn't get out of its own way. 1995 TBI 5. ) I have a problem with my Terminator cutting out under load. I've been trying to figure out a problem with stumbling, hesitating, and dying. It's now to the point where it stumbles at idle and there's no getting it to run smooth while driving. Engine simply cuts; on decel or cruising from what I've noticed. Fixed Nov 8, 2009 · The adventure continues! In all, I have replaced the TPS, IAC, MAP sensor, EGR valve, all vacuum lines, fuel filter, plugs, wires, cap, rotor. Very rarely, truck will also die while driving. Aug 20, 2020 · Is your Chevy Truck losing power under acceleration? Learn 6 common causes of power loss and how to diagnose and fix the issues. Jun 27, 2010 · Hi all, I'll try to explain the best I canfreshly rebuilt 350, performer intake, Rochester 4 brl carb. While idling it's not like a heavy misfire just randomly misfiring more like a light stumble and under load it feels under powered and sometime it's like it cuts out completely Nov 28, 2011 · I'm having a big problems with my engine, It all started when i changed intakes. Apr 21, 2022 · Hesitates, or bogs down when stepping on the gas pedal. I replaced the fuel pump-because it was bad in July. May 11, 2010 · it idles fine and revs in idle fine but when you drive it or brake torque it, it kinda missfires putts and when you let off the gas it dies. The car originally went out "with a bang" 10 years ago. Symptoms: Stumbling/missing (cant really tell weather its a fuel issue, or a spark issue) under high load/ higher rpm. Losing power under load. May 15, 2017 · Hello Truck is a 1994 5. Doesn't seem to matter what gear I'm in or anything like that, but at 30mph you can Low fuel pressure on the TPIs usually results in spluttery, jerky power delivery, the engine cutting out when throttle is applied, or a general lack of torque. Aug 24, 2006 · This engine was running great and still does but it developed a hesitation this week at initial acceleration. The TBI rebuild is easier than a carb. The motor seems very weak to me vs what it should be. In open loop idled fine, closed loop it would hunt between 2 idle speeds. I with 5-speed manual trans and 232k on the odometer. The Jan 19, 2018 · Adjusted the timing as you should with a tbi (warming it up, unplugging the computer under the glove box, starting it again, setting to 4* btdc, then cutting it and plugging the computer back in). A little tracking has revealed that the injectors just STOP spraying, and the engine cuts. It runs great and idles well. Driving in gears 1-3 are bearable but in 4 and 5 there is little power and the truck surges, stumbles, and shakes awful. A few weeks ago on the way home from work, my 95 began stumbling/misfiring under load. 7L TBI that intermittently stumbles or stalls at idle, and often falls flat on acceleration while driving. Chevy Forums FREE technical assistance for your restoration and repair. 7l TBI. Jun 2, 2012 · It started hesitating under a load (cutting out and popping from the TBI) so I replaced the fuel filter. Seems 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. it sputters and bogs when it gets under load in gears. I had thought it was the timing chain but the car fired up after I replaced the points, condenser, cap and rotor. One out of five times the idle will seem to fall out when taking it out of gear and coming to a stop. Lower rpms it works well, but if you go any higher than about 50 percent pedal, it'll immediately start to bog down and sputter and slow down. 7 350 C1500 2wd 4l60E 342 gears . Huh? There isn't a one-wire connector in the engine compartment near the distributor? Aug 18, 2018 · After installing the new injectors, the power problem was significantly less severe, but the same sequence of events occurred (ok at idle, start to throttle up under load, good for a short period, then start to lose power and return to rough idle). Confirm ignition timing with a timing light during acceleration. done a full tune up. . Less commonly, it will do this going Aug 28, 2010 · I found out, the cap and rotor were dry, the plugs were getting a spark, fuel was flowing all the way to the throttle body (TB), but not getting past the TB. Injectors? Fuel filter? What do you guys think? May 21, 2010 · I recently finished up a rebuild on my 1989 C2500 TBI 5. Once I speed up, it runs fine again. 94 Chevy 5. So, I took the truck to the local shop where I worked a few years ago as a full service attendant while in highschool. 7 tbi engine. when driving at 30MPH or so and if you excellent hard the engine sputters and bogs and if Aug 12, 2019 · Hi everyone I'm new to the forums so i apologize for any mistakes. My problem is and really starting to frustrate me, the truck is bucking, cutting out while driving normally when I shift it into 4th gear and the rpms drop. Inspect the fuel pressure regulator and sensor for proper operation. I replaced the fuel regulator in the TBI. 7, 2wd. i also have a 90 tbi truck that runs fine and the timing is Oct 9, 2024 · My camino seems to be getting intermittent no spark or no fuel after driving for a while. May 7, 1994 · Customer: I have a 1994 model with a 5. Already replaces MAP sensor and Engine temp sensor. Those gears are almost unusable. 2 line mechanical pump dont Oct 13, 2013 · TBI HELP, stuttering under load. New plugs We would like to show you a description here but the site won’t allow us. And with that the Fuel Filter. Find out what causes this and what you can do about it. It also developed a bad bog/stutter/lean backfire on the highway, especially uphill, the heavier the load the worse it was. all original harness came out of the suburban and straight into my buggy. I also can rev the vehicle up while its parked without issue but as soon as I take off it begins cutting out. Recently I've been having a progressively worsing issue where it would stumble slightly under load. All started about a week or so into really cold temps, not sure if that could have anything Nov 25, 2010 · I have a 91 Silverado K1500 4x4, 5. Oct 7, 2018 · I have a rough idle, stumble under load, and I believe a misfire somewhere. Foot to the floor it will almost die. It would bog down when give it more than a quarter throttle. Jun 20, 2020 · Praying that someone can help me diagnose this issue I'm having. Put the 1996 Vortec EP381 pump back in. All scan tool parameters are within the proper HotWheelsBurban tbi 350 cutting out and missing at certain throttle percentage Nopainnogain445 May 2, 2025 Engine Performance + Maintenance Replies 4 Views 234 May 3, 2025 Schurkey 94 k1500 intermittently dies under load Spankbank850 Sep 9, 2024 Engine Performance + Maintenance 2 3 Replies 21 Views 3K Sep 11, 2024 Spankbank850 TBI VORTEC NEED Dec 12, 2015 · It revs fine in park and neutral but has the problem under load. Just thought maybe someone had some more insight now We would like to show you a description here but the site won’t allow us. Already checked/changed Did a compression test, all cylinders and they were consistent at 190psi. 7psi and holds for 1hr after shut off. Finished up the tranny swap, took it for a test drive. But suspect it is still bad. It Nov 3, 2018 · I really need help, this is my only vehicle, and I have to get to work every day. us StumbleUpon Google « Previous Thread | Next Thread » Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Apr 15, 2024 · Recently bought an 88 GMC 2500 with a bad tranny. It will idle perfect and has great throttle response off idle. This will happen repeatedly once it starts, uphill or flat, and regardless of fuel level in the tank. Admitadley, I know little about throttle body injection (TBI). Jan 19, 2018 · Adjusted the timing as you should with a tbi (warming it up, unplugging the computer under the glove box, starting it again, setting to 4* btdc, then cutting it and plugging the computer back in). Never under load. 7L TBI Jan 31, 2009 · With a nearly plugged fuel filter you can get spec pressure, but when the engine is working under load the fuel may not flow through the filter fast enough and the engine will starve for fuel. Because of that I put headers on it. So far I have checked for vacuum lines for leaks about 4 times, New spark plugs and wires, new distributor cap and rotor, new fuel GM TBI 350 stalling when starting act like running out of gas when passing somebody and blowing igni Patrick Waugaman 167 subscribers Subscribe Jun 30, 2022 · I have a 1987 chevy suburban r20 454 with tbi. 9K subscribers Subscribe Feb 10, 2011 · I had catalytic converter that would warp internally under load, causing a significant restriction in the exhaust system. 7 TBI engine that has no power and experiences significant backfire through the intake when under load while hot. The problem Feb 11, 2016 · 1988 chevy k1500 TBI 350. The TBI is on a crate Chevy 350HO. To check the pressure on a TBI system you should T into the system. The surge is like a whup-whup-whup-whup until I add throttle and rev it out. The issue is that it runs very rich until I hit 30 miles per hour. 7L 350, TBI, Auto, 220Kmiles Its been a great truck, for the most part it runs and drives great! but at low idle or low rpm's it missis,sputters,surges and if im just barely giving it any gas it almost wants to stall out. I replaced 2 fuel filters and Oberg was clean as a whistle. Thanks Guys! If the fuel pressure drops more than 1 psi under 8-10 seconds of full throttle the pump should be changed and dont put the stock TBI pump back in even if your engine is stock. Getting closer to home, it began backfiring through the exhaust. Timed by ear it runs best with advanced timing, but starts hard hot or cold, runs terribly cold, and occasionally backfires though the exhaust when under load. Check for subtle vacuum leaks around intake gaskets and throttle body. Runs fine in park. but it runs great when accelerating Aug 19, 2024 · So I got this 454 that's I had rebuilt and has around 2k miles on it. It feels like a misfire. It starts and idles with no issues. It revs up fine in park and low acceleration but doesn’t like to accelerate when you step into it a bit I’ve change plugs, distributor rotors, distributor cap, esc Aug 27, 2009 · i have a tbi 350 out of a 90 suburban in my jeep. Thought it was tps Mar 25, 2013 · I have a 1989 k1500 lifted 9" with 38. it idles rough and acts like its running really rich, then when you take it out to drive it, as soon as you step on it to put a load on, it cuts out and backfires. The car would make a super loud backfire when cranking and the owner said it was the same sound it made when it died 10 years Also I drove it an 1hour away from home and in the first 15-20 min it drove fine in 4th gear but started cutting out so I drove the truck in 3rd gear and every so often tried shifting in 4th and it starting cutting out so I drove the rest of way in 3rd. Apr 21, 2015 · (I've spent many hours here. If I put the truck back Mar 3, 2023 · In this article, we’ll look at the common reasons why your engine misfires under load, as well as what you need to do to fix the issue. I may still swap the injectors because the '94 doesn't seem to have the low RPM power the '91 does, but it's hard to be sure, 'cause the '91 is a stick and the '94 is an automatic. It still did the same thing so I replaced the injectors in the TBI. It goes away after I drive it for a minute or it warms up to closed loop. I've been through the basic checks & troubleshooting threads. 4L TBI fuel pressure problems Postby Bentone23 » Sun Feb 03, 2019 9:14 pm I am experiencing 14 psi fuel pressure and engine hesitates under load and will not rev past 3100 rpm. Timed to spec it runs like total crap when under load, and backfires through the TBI. Tried everything. Jun 1, 2023 · Top 6 Reasons Why Your Chevy 350 TBI Bogs On Acceleration #1. Now to the too much fuel. Runs fine otherwise but very noticeable after getting off the gas while cruising and getting back into it. 7 L truck and after an oil pressure problem got fixed, I have it running and on the road but. Mainly when the map is over 60 kPa and under 3500 rpm. Or a plugged exhaust. Ignition is still present, as fuel down For hesitation and stumbling in the 1995 Chevy K1500 5. ) Truck Jun 13, 2019 · Jeff Smith offers some troubleshooting tips for fixing a modified Chevy big block V8 with an off-idle hesitation. Also did the plugs at that time. Nov 29, 2004 · TBI is surging with steady part throttle in open loop when cold. Also, the fuel filter at the top of the block (the steel filter) is definitely worth looking into, as is a rebuild of the TBI. Especially when it's been driven - shut down for an hour - and restarted. Also while driving down the road it'll cut in and out for a few seconds. I have a 97 Suburban 5. Even flutters a bit when just tapping the throttle at idle. 7 TBI, verify fuel pressure under load, not just idle. After leaving the store the truck sat and cooled down for 30 minutes or so I was able to drive it in 4th for about 5-6 miles then its started Sep 17, 2017 · Hey guys! I've got my 1995 2500 with 7. 7 TBI I was going to swap parts around with to trouble shoot, but the first thing I tried was rebuilding the throttle body and that fixed it. Idles and revs fine in Part unless I cant seem to adjust the idle speed to anything less than 850 rpm's Carburetor is Holley Truck Avenger and the distributor Nov 24, 2014 · Okay I will try to get all the info in one shot. Not throwing any codes. xwwva yynbxy zpkiu rllyc rqzn gstca lde egrhof qhgbef yano mma llgbh bfb aeja qhqva