Chevy 305 tbi stumbles on acceleration. Car used in this Jan 15, 2021 · I would check the fuel pressure, kinda sounds like a weak fuel pump struggling under load. It will help you make decisions about maintenance, repairs, and even purchasing a used car. It feels like a misfire. My 91 TBI 350 Jimmy hesitates on hard acceleration. Thought it was tps Customer: I have an 87 Chevy truck with a 305 engine throttle body. It's now to the point where it stumbles at idle and there's no getting it to run smooth while driving. 7 TBI engine. It sounds like it wants to choke out and die but then it starts to accelerate. I have replaced the temp sensor Oct 7, 2012 · Hey Everyone, I have a 91 V2500 with a 5. after that its gone (and so is the May 20, 2010 · Cliff-notes below. I have a 1995 Chevy S-10 4x4 ,4. Nov 15, 2005 · ok i have a 96 blazer with a 4. If you accelerate gently, not too noticable, but when you accelerate hard, it hesitates pretty badly. Cap & Rotor & Fuel Filter. When hot, and under hard acceleration, I get a bit of a stumble like it's either loading up or starving Oct 20, 2005 · Fuel pressure for the TBI ('82-'84) is 9-13 psi, whereas fuel pressure for the TPI (LT1) is an operating rating of 50 PSI and 24 GPH. 7 Vortec 2 door 4x4 Tahoe. I replaced the fuel pump and when I turn the key on the pressure builds up but doesn't hold. This goes for all vortec 4. I'm not surprised you blew the TBI out. Or a plugged exhaust. Foot to the floor it will almost die. 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. The surge is like a whup-whup-whup-whup until I add throttle and rev it out. Also there was another guy on here a while ago with a 99 v6 and a similar problem, replaced all kinds of stuff and found out it was a worn distributor drive gear. Apr 24, 2015 · The TBI ECU’s narrow band O2 feedback system oscillates the AFR rich-lean-rich-lean-etc. That fixed the stumble and stalling issue. 8K views 22 replies 4 participants last post by bigdadhack Aug 27, 2022 Aug 26, 2009 · i have a tbi 350 out of a 90 suburban in my jeep. 5 roller rockers. Have also replaced the O2 sensor and EGR electric solenoid (believe it is the simple on/off Feb 25, 2025 · If either system is restricted or malfunctioning, the engine can struggle to draw in enough air or expel exhaust gases properly, leading to hesitation, poor acceleration, and even engine stalling. 030 over stock rebuild with a Rochester 2GV carb and HEI distributor. Starts fine, even today when it was -15, fuel pressure 52 running, holds after shut down, newer plugs/wires/cap rotor, tested MAP sensor and tests good, tested resistance changes in TPS (with sensor out) and changes were smooth May 23, 2016 · Hey everyone, We bought an '89 Chevy K1500 with a 350 in it and 224k miles, with the nasty Getrag trans I knew nothing about until after purchasing the truck. I would like to know if anyone has power boost ideas without spending a lot of money. Engine is a . 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. 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. Check the distributor cap and rotor for wear or moisture, inspect spark plug condition and gap, and examine vacuum lines for cracks or disconnections. Dec 25, 2015 · Thank you in advance for all who reply. 7L TBI intermittently stumbles/stalls at idle, and frequently falls flat on acceleration down the Nov 24, 2014 · Okay I will try to get all the info in one shot. May 20, 2010 · I've been trying to figure out a problem with stumbling, hesitating, and dying. My truck randomly stalled on me about a week ago. I've been having stuttering/bogging issues when giving it just light throttle. At idle in park it has an intermittent miss. Unplug the tan/black wire, time the engine to ZERO degrees and reconnect the tan/black wire. 7L 350, TBI, Auto, 220Kmiles Its been a great truck, for the most part it runs and drives great! but at low idle or Sep 11, 2013 · my 454 idles fine, runs good at parking lot speeds, but when punched, hesitates and stumbles terribly until 3000 rpm when the secondaries kick open and it runs great. Apr 20, 2014 · Chevy TBI 350 stumbles on accelerationI hate to sound like a broken record, but on a Chevy TBI engine, the timing needs to be at ZERO. Sep 4, 2014 · A bit stumped on fine tuning my 5. 7L. The truck idle drops and lopes Chevy truck hesitates when accelerating? Discover the causes of acceleration hesitation and how to diagnose and fix the issue in our comprehensive guide. A week or 2 ago the truck started missing and surging anywhere but idle or wot. At idle in drive, its very smooth with no miss. Aug 17, 2020 · Hey all, it seems like everyone with a TBI motor is trying to fix bad idle, lack of power, and poor fuel economy, I'm no different. Didn't 305 tbi, dosnt burn oil, starts fine, runs good for 2 or 3 miles, then boggs down and coughs when I depress gas, acceleration real bad for another 5 miles then it runs a lot better but still has hesitation under initial acceleration this problen just started last week and gets worse each time I drive it. And At very low load, rpm between Aug 9, 2012 · I've looked in all the forums and I find people with a similar problem to mine and have tried their fixes with no luck. Nov 29, 2004 · TBI is surging with steady part throttle in open loop when cold. Feb 17, 2020 · 1991 K5 TBI 350 with SM465. acceleration Sputtering and popping was the first indication of trouble with mine (see: Another one not running). Lately, once she’s warmed up, I’m noticing an issue: if I hit the gas, it bogs down and feels like it’s about to stall before it finally catches and goes. I also have another 5. Getting closer to home, it began backfiring through the exhaust. 7 TBI motor. Discover other causes of this phenomenon and their solutions here! Apr 5, 2004 · '94 4. Stumbles and runs rough at lower throttle positions (just off idle). Nov 1, 2006 · My truck (in sig) just developed a bad stumble on acceleration. Ive got a 94 chevy k1500 305 with tbi that has been stumbling (or choking) on acceleration. changed plugs, still happening. I bought a throttle body gasket kit for 20 something bucks on Amazon and rebuilt it. 7 TBI, bone stock. 7 engine. If a TBI motor is not at 0° you have problems with acceleration because the computer takes over advance/retard of timing from 0. Upon pressing on the gas pedal it starts to stumble. Here are a few potential answers: 1. Also while driving down the road it'll cut in and out for a few seconds. 300k on the ODO, swapped in motor has 180k. All of this is in my ’72 Chevy pickup. Aug 26, 2016 · I’ve got a Chevy small block 350 with a mild cam (I don’t know what the specs are – I bought the engine used), an Edelbrock Performer intake, Holley 750 vacuum secondary carburetor, and headers. Also stumbles a May 5, 2015 · 1996 c1500 Chevy Suburban 5. 0 5. It has a slight miss at idle but gets alto worse under load. 7L TBI, I've replaced the Timing Chain & Gears, IAC valve, TPS, MAP, EGR & Solenoid, ES Module & Knock Sensor, ECS, Ignition Module, Plugs & Wires, Dist. It starts easily, and within seconds revs to 2300 rpm and stays there. Idle is good and WOT seems normal (will spin the rear tires and sounds like it's hitting on all 8). I had a problem with my engine bogging down when I accelerate. And the truck seems to be low on power when at wide open throttle even when warm doesn't Jan 5, 2022 · Replies 4 Views 877 Mar 23, 2025 Schurkey 1988 4. After letting my 1996 Chevrolet 1500 work truck with 5. ) I’m in California and subject to smog Aug 11, 2025 · Car engine hesitation is when you step on the gas pedal and your car stumbles or doesn't accelerate right away. Jul 9, 2017 · To fix this hesitation problem with it on my Chevrolet truck, we replaced the fuel pump, the catalytic converter, and the distributor. I. Feb 11, 2016 · 1988 chevy k1500 TBI 350. No problems starting engine, no problems at higher rpm. This is the accelerator pump linkage arrangement on a Holley carburetor. One out of five times the idle will seem to fall out when taking it out of gear and coming to a stop. I’ve had a problem with my truck accelerating from a stop to 10-20 mph then it goes just fine. You may want to "rebuild" the TBI's. Driving in gears 1-3 are bearable but in 4 and 5 there is little power and the truck surges, stumbles, and shakes awful. Timed to spec it runs like total crap when under load, and backfires through the TBI. Idle is fine (smooth) and gentle cruising regardless of speed where very light pedal pressure is fine (smooth). I rebuilt the throttle body and replaced the spring in the regulator and it still won't hold. Feels like it wants to break through. And This is a video about rough acceleration rough idle low idle and possible stalling Oct 5, 2007 · Guys, I'm stumped here, HELP! My '65 Chevy pickup with a basically stock 305 and turbo 350 has had a hesitation since day one. Any help would be appreciated. 1995 TBI 5. Oct 19, 2017 · 95 GMC TBI 350 accelerating problems Jump to Latest 25K views 22 replies 7 participants last post by Zach Smith Nov 15, 2017 C Jan 20, 2018 · 1991 GMC 350 TBI Engine stumbles and dies at idle after warm up mjordan May 14, 2018 May 15, 2017 · I have a 1994 sbrc 2wd 5. Especially when it's been driven - shut down for an hour - and restarted. The whole time I thought it was the carburetor or fuel pump it’s actually in the distributor! I have a 1988 Chevy C1500 with a 5. New MAP, EGR, O2, TPS, ESC, distributor and coil. In the last year I have been struggling to fix a consistent hesitation I get under acceleration after it warms up. But, upon any harder acceleration, I'm getting the most God-Awful sputtering misfire I've ever encountered! I swear it's like somebody Nov 24, 2013 · Drop in Idle and/or stall when gas released - I have been working on our 89 Chevy K1500 and am still having an idle issue. It starts and idles with no issues. 7 TBI Chevrolet Jump to Latest 17K views 46 replies 11 participants last post by munderhill Apr 15, 2015 munderhill Discussion starter Jul 20, 2023 · I have a 87 Chevy R1500 w/ 350 TBI. This morning the truck drove great with only a few light stumbles, on light acceleration, as I went to church. Found throttle position sensor intermittent contact. it sputters and bogs when it gets under load in gears. 7 350 C1500 2wd 4l60E 342 gears . And just now I was trying to accelerate when not only did it stumble, but I heard what sounded like a back fire coming from the engine Customer: I have a 1987 R10 with a TBI 305 automatic that has been stumbling badly during light acceleration since I purchased it around 2000. 7 TBI I was going to swap parts around with to trouble shoot, but the first thing I tried was rebuilding the throttle Aug 21, 2002 · What would cause TBI engine to sputter, hesitate, skip and misfire/backfire Chevy silverado 5. Understanding the common problems with the Chevy 305 engine is essential for maintaining the health and longevity of your engine. It will correct itself after about 5 seconds, can usually correct it a little quicker by revving. Mar 14, 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. I've seen multiple times the ICM (Ignition Control Module) will wig out once the engine warms up after a while (don't use Chinese junk parts). 3 W - CMFI Motor - Bad Hesitation during Acceleration Jump to Latest 12K views 19 replies 9 participants last post by BlazerLT Apr 8, 2004 B Jan 17, 2022 · So I replaced the icm, map, egr solenoid, with acdelco parts. Jan 31, 2009 · Replaced them and I started to get symptoms like most other S-10's (bogging down, hesitation on initial acceleration, if i put in reverse would even occasionally stall). I have messed with timing and checked for vacuum leaks and cant find anything so I decided to turn to the most trusted people on the internet you guys. the engine will stall when coming to stop at a Jul 24, 2013 · New to the forum with (maybe) an old problem. At slow speeds and under load the oil pressure drops to 5ish and stalls out. I put shorty headers on the truck so I am going to put the O2 from the y pipe to the Oct 3, 2007 · I have a 2000 Z71 Tahoe 5. Remember, there’s “only” 200 hp moving a 3 ton truck. I broke in the cam on the new engine (SBC 400) with the sniper and dual sync, also with really no issues. Nov 8, 2009 · My 95 chevy has the TBI big block in it, and it has a miss to it. Runs fine otherwise but very noticeable after getting off the gas while cruising and getting back into it. I have replaced the plugs and wires. The motor seems very weak to me vs what it should be. any Feb 19, 2009 · 1992 4. With the timing set, now you can see if the acceleration hesitation is still present. Feb 23, 2010 · Hello i have a 1967 el camino 327 small block with a rochester quadrajet carb and a turbo 400 trans. 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 In this video I diagnosis and fix a bad misfire on my 1975 Chevy C10. Any ideas? I suspect the Friends, I am desperate, I tried everything I know and more but I cannot find a solution to my Loping idle and surging acceleration on my '90 Sierra C1500, 5. It would stumble and sometimes stall at light throttle just off idle. When you set it to anything other than 0 you confuse the system. It idles smooth, and revs up in park perfectly fine. I have 1994 GMC Suburban with a 5. rebuilt carb, got new carb from jet, checked timing, changed distributor. If the fuel filter is clogged or the fuel pump is not working properly, it can cause the engine to bog Jul 18, 2008 · Of course, andy 19 year old cheap used car is gonna have some "imperfections" and the first one I need to fix on this 89 RS is a VERY high idle. Idle May 1, 2020 · Ive been running a Holley Sniper for a about four years now. 350 turbo trans 3500 stall 411 gears holley 850 double pumper. I've replaced the ECR valve twice, which provided temporary improvements that lasted about a season. I also can rev the vehicle up while its parked without issue but as soon as I take off it begins cutting out. Apr 16, 2020 · I have a 1989 Chevy 1500 Cheyenne with a 305 in it. It acts like its losing power & Jun 19, 2015 · Hesitation on acceleration The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board A series of troubleshooting tests chasing the reason for the engine bogging down hesitating while trying to achieve full throttleAmazon affiliate links-Aweso Nov 28, 2011 · I'm having a big problems with my engine, It all started when i changed intakes. Oct 20, 2009 · Got an all stock '93 Z-28 automatic with 133K mi. I ran a datalog with WinALDL and the only thing that stood out to me were a bunch of Aug 3, 2024 · 1994 chevy suburban c1500. It just has a slights stumble at very low throttle before say 1500 rpm. The truck hesitates and stumbles BAD when I lightly apply the throttle. Because of that I put headers on it. The issue is this: lately, it simply will not start without starting fluid. 7L vortec v-8 and 4L60e trans (203K on the engine, recent rebuild on trans) sit in the driveway for a couple weeks, I hopped in to head to the parts store. It has been swapped with a 1989 Camaro 305 that has a roller cam in it. Apr 21, 2022 · Hesitates, or bogs down when stepping on the gas pedal. 5:1 flat tops scatt crank and rods, 630 lift solid roller cam with 1. - The 1947 - Present Chevrolet & GMC Truck Message Board Network > > Nov 24, 2010 · I have a 91 Silverado K1500 4x4, 5. Coming home, it had a rough, surging idle on startup, and a lot of stumbles all the way home. This is a follow-up video to my question about the GM 5. Does not do it with the timing wire un hooked Learn how to boost the power of your 305 engine with these budget-friendly mods and tips. Newer fuel pump, new fuel filter. The engine revved car sputters while accelerating?in this video I show how to fix a hesitation and/or bogging issue with carburetors by adjusting secondaries. Jun 16, 2020 · The TBI trucks are bad about the EGR valve going bad, opening too soon, causing a hesitation off-idle and a rough running engine. The Jan 3, 2012 · My truck: 1989 Chevy K1500 5. 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 Sep 7, 2015 · Symptoms Slight misfiring at idle, inconsistent RPMs Main issue: Stumbles/hesitates severely under load, especially with high throttle, below about 2-3k rpm (sorry no tach) Surges around 2-3k rpm Normal power above 2-3k rpm Car was left sitting for 6 months between problem starting and me getting it Engine codes (KOEO 111 - normal, KOER 412 & 413 - idle low & idle high) Cooling fan doesn't Apr 25, 2025 · Chevy 350 TBI bogs on acceleration because the fuel delivery system is blocked. Feb 20, 2018 · T. Jan 30, 2025 · Discover common Chevy 305 engine problems, their causes, and insights from owner feedback and recall campaigns. 6K views 6 replies 5 participants last post by dougs85 Jun 15, 2008 T I'm dealing with an intermittent stumbling/cutting-out issue lately. Today though it started missing under load . I have a 1995 Chevy K1500, 5. I thought it was because of an exhaust leak so I tried to repair it but broke stud. Accelerating it Mar 21, 2021 · My 1995 Chevy 350 stumbles when I take off from a stop. 7 tbi 4l60e. When installing I found out the firing order was backwards. For example, sitting at a stoplight, as soon as I press the gas when it turns green, there’s a About 3 weeks ago, I noticed a stumble/hesitation when accelerating from a stop light. The problem Subscribed 1. Sep 28, 2021 · Is your Chevy Truck losing power under acceleration? Learn 6 common causes of power loss and how to diagnose and fix the issues. Then plug the EST wire back in. It would bog down when give it more than a quarter throttle. It starts and idles fine, but cold or warm, it hesitates under acceleration. If I take a ten mile Aug 24, 2006 · This engine was running great and still does but it developed a hesitation this week at initial acceleration. 7 tbi. replaced runs great now. 7L developed a hesitation/stumble with light gas pedal pressure shortly after startup. This condition can occur at any speed, but primarily from a stop. The truck runs great except for a stumble when you first step on the gas from a dead stop. It's a 89 k1500 5. 3L, VIN W. It has no power when it does this. Fuel filter. 7l 350. Having the timing advanced or retarded will cause problems, including hesitation, bogging or even misfire. Once I speed up, it runs fine again. I have a 1994 GMC Sierra 4x4 with the 5. Has a quadrajet carb, new fuel pump and filter, new points, condensor, new coil. 3L TBI - Complete new fuel system, still misfires through intake manifold upon acceleration/ load chevy__jones Aug 11, 2025 Engine Performance + Maintenance Replies 0 Views 187 Aug 11, 2025 Customer: hello. I have advanced my timing, tried to adjust the Feb 20, 2015 · Hello, I am hiving a issue that I have been trying to fix for some time now, from a stop in hard acceleration my car bogs very bad. B. Changed the distrubutor cap, rotor button, fuel filter and in-tank (holy Nov 29, 2022 · I have a 97’ k1500 with a 5. Aug 25, 2011 · Here we go again. It has been going on from the first time I drove it after the rebuild. I did find the rubber link hose to the MAP sensor and canister purge line were cracked which Feb 3, 2015 · I have a 70 Nova with a sbc 383 with 10. May 16, 2021 · Installing some key pieces to stop pesky hesitation problem during acceleration after you did a initial tune up such as spark plugs and wires rotor and cap but you still have symptoms of Dec 6, 2022 · Signs indicating a problem include rough idling, jumpy or sluggish acceleration, poor fuel economy, and stalling. Fixed TBI being a MAP sensor based system will see the leak just like opening the throttle blades and will feed the leak and then you have a high idle. And with that the Fuel Filter. It has TBI and idles rough and has hesitation when accelerating from a Aug 12, 2019 · It s/b 9 - 13 PSI (according to GM specs), at idle and under acceleration, preferably 11 - 13PSI. 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. Jul 19, 2009 · The engine is a 1969 350 chevy. Truck sat for about 7 yrs and am getting it road ready for my nephew. Shouldn't it hold pressure and not drop off? May 3, 2010 · 1995 Silverado, 2wd Air, 5. I have a 97 Suburban 5. Jun 1, 2023 · Top 6 Reasons Why Your Chevy 350 TBI Bogs On Acceleration #1. this engine came from a junkyard and it looked rebuilt. I've ran the Sniper EFI system with the Holley dual sync on my old engine (SBC 350) with no issues. Very shocking because it's never done that. Runs great down the road, and doesn't miss at all, however when giving it very light throttle it misses pretty good. Also went to the treasure yard and found a much lower mile tbi 350 and I pulled off the tbi unit. SES light comes on every day now. Rough idle is probably TBI related, especially since you over-pressured the TBI. It's somewhat intermittent, but it's doing it Jul 17, 2020 · The TBI motor does it’s best at just off idle to maybe 3500 rpm, then the swirl port heads plumb run out of breath. Driving around in low rpm's everything is fine. Heres my problem: If i accelerate my car from a dead stop the car hesitates upon acceleration from idle to say 10% acceleration, then it bucks forward. 7 liter vortecs. to drive the narrow band O2 between (approximately, but usually) . On hard acceleration it is bogging down like there is to much air, because sometimes it backfires. Compression is 118psi to 120psi and fuel pressure 10psi 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. It also has an aluminum intake with a 350 Tbi that has been ported with a spacer. It does have allot of miles on it (275,000) but for the most part it runs like a clock. 3 TBI. Hello I'm a new member. I have a new to me 1996 5. Oct 24, 2014 · Hi, My first post here. The most common causes are Aug 20, 2022 · 91 350 TBI, Open loop part throttle hesitation #coldstart open loop tbi Jump to Latest 4. 7, 2wd. If your car or truck is equipped with a Holley four barrel carburetor and stumbles upon acceleration, more than likely the carburetor needs an adjustment to the accelerator pump assembly. I can get it to run but have to push on the throttle and it won't idle. Common issues, but the only problem is that there is rarely ever just one magical cure-all to these issues, people think they have the answer because it worked for. 40k on trans. Dec 4, 2012 · 1990 chevy c1500 hesitation and stumbling during acceleration unresponsive to gas peddle at times and has major dead - Chevrolet 1990 C1500 question Apr 14, 2018 · Hi there, Finally got my Chevelle out of the garage with the new engine this morning. There are various actions you can take to attempt and fix the problem if your TBI-equipped car exhibits idle surge and stumble. Apr 19, 2014 · On a TBI motor with Electronic Spark Timing, you unplug the Tan/black stripe wire next to the brake booster to disable the EST and time the motor to 0°. It goes away after I drive it for a minute or it warms up to closed loop. I have replaced the ECR valve twice with temporary improvements that may last a season. 7 hesitates under load. Assuming the hesitation is annoyingly still present, now we can turn our attention to the carburetor and accelerator pump. Engine & DrivetrainT. Even flutters a bit when just tapping the throttle at idle. 3L TBI Hesitation/Bog Under Load Jump to Latest 21K views 6 replies 5 participants last post by lesterl Mar 1, 2009 92S10Tahoe Discussion starter Dec 13, 2010 · 1994 S-10 4x4 pickup, 4. Plugged the Oct 29, 2009 · Even when I'm not moving, just idling and hit the pedal hard there is a noticeable hesitation. A few weeks ago on the way home from work, my 95 began stumbling/misfiring under load. A few days later it began to stumble and hesitate upon acceleration. i bought it 2-3 weeks ago, so i know next to nothing of the Nov 22, 2008 · 2002 Chevy Tahoe LT 4WD 1997 Chevy Tahoe with 2002 Tahoe front swap bagged on 22s ///RA TENNESSEE CHAPTER. I have a hesitation/power problem on acceleration. It's OK at steady speed, but not great. The symptom is a bad misfire / no power under load when accelerating. 3 5. Sometimes the idle would dip low briefly, then recover as I came to a stop. Anyway, we have been chasing a rough idle ever since we got it. Well, it didn't seem to idle rough until a few weeks after we bought Jan 28, 2004 · Need help! I have a 1990 Chevy TBI 350 in my FJ40. May 15, 2017 · Hello Truck is a 1994 5. It stumbles and backfires when accelerating. during the evening once it has cleared up and is running fineit will continue to do so even after setting for 2-4 hours. Less commonly, it will do this going Apr 14, 2025 · Explore common Chevy 305 engine problems, their symptoms, and consequences to keep your vehicle running smoothly. It also Jun 30, 2022 · I have a 1987 chevy suburban r20 454 with tbi. I have new wires, plugs, accel ignition coil, holley fuel pump, fuel filter, points, cap & rotor; around 100 miles on these parts. 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. 7 TBI with 306,000 miles on it. Engine specs 97 chevy tahoe 5. I get a code 44 lean condition. Stumble/hesitation on accel. Other than idling at 2300 rpm, it runs very Aug 19, 2015 · 1995 GMC Suburban, 5. not that it matters, but its a 4x4 and LT package. The Aug 21, 2019 · I just repaired a similar problem on my '94 K2500 5. I have had numerous mechanics look at the Jun 2, 2008 · Howdy - My father in law's '91 Chevy was running poorly, so we put new plugs, wires, cap and rotor on it, and it's running better, but it it still surging at idle. Vehicle may also experience a surge or rise and fall of engine speed at cruise or steady throttle. The problem I'm having is Jun 9, 2023 · Hi fam, long time Chevy owner, first time posting. Engine & Drivetrain Apr 9, 2010 · 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. 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. I replaced the fuel pump-because it was bad in July. 8K 251K views 6 years ago Chevy GMC tbi engine flooding hesitation smoking running rich running bad diagnose and fixmore Feb 5, 2011 · Just joined GMTC today in hopes of getting some of your input on the issues I've been having on my Sub. 7L, about 235,000 miles on original motor. Mechanic's Assistant chat Customer: I have had a 1987 R10 with a TBI 305 automatic which has stumbled badly on light acceleration since I bought it in 2000 or so. It seems to be worse under moderate acceleration. Check Vacuum Lines for Leaks: A vacuum leak in the intake system is one of the most frequent causes of idle surge and stumble. 7 350 TBI motor (4x4 with 4L80E transmission & NP241C transfer case). 0 L engine. It's pretty much always there, I can get it to behave a bit once I'm moving but that's really only between 20 and 40 mph and that's by hitting the sweet spots 1993 Chevy K1500 5. 7. This is a 305 with a 2bbl TBI. 215,000 on the truck, 40 or so on a GM crate engine. As long as I stayed under about 1/4 throttle, it was okay. The TBI and engine are stock. Once it has been running at temp for 20 min. Recently I've been having a progressively worsing issue where it would stumble slightly under load. Got timing roughly set around 0. It basically almost dies out, and then surges back to life (probably a little higher than normal idle), then repeats continuously Jul 5, 2012 · Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly. I've also changed the O2 sensor and the EGR electric solenoid, which I believe is a simple on/off type. Cap, wires and plugs unknown (they look heavily worn. 1 volt and 1 volt. If I rev it up and hold it at about 2 to 3 thousand rpms its fine and revs up fine. Installed stock rebuilt engine a few weeks ago. My truck is a 1991 V-1500 Sub, 5. 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. 7L 350 4x4 V8 I'm new to this forum so forgive me if I break any rules. Jan 2, 2001 · Problems: When the car is cold, it stalls often until warm, idling is very rough, acceleration is rough, almost doesn't accelerate until you find the right spot in the pedal, once warm the car has a intermittant pulsing idle, jumps from 500rpm to 1500 rpm, and occasionally will stall at a red light. Visit Pinpoint Air today and get started on your scrapyard build! Engine hesitates or stumbles on acceleration, sometimes stalling. After this starts, it also develops a problem idling, by surging and slowing until it stalls. Its been running pretty good until a couple of months ago when i noticed a slight hesitation when accelerating. Sep 4, 2007 · Got a 68 327 with rochester 4 bbl carb (new) recently the car (engine) stumbles off the line thru to about 2200 rpm. but once I take off from a stop it starts missing Jun 20, 2020 · Praying that someone can help me diagnose this issue I'm having. Problem is engine starts and idles The most common question we get during our Wednesday Night Tech Talk Live shows has to do with carbureted engines and poor off idle and low speed performance Dec 21, 2008 · Please help me diagnose this problem. Unplug mass air flow sensor restart truck and drive to see if Nov 3, 2018 · What's the fuel pressure do when you open the throttle body? Fuel pressure at idle is fine at 10 PSI (if I recall correctly for the TBI 10 works, but I do remember my old TBI running closer to 12 or 13), but if the pressure drops drastically during acceleration it could cause the problems you're having. Find out what causes this and what you can do about it. 7l Backing firing thru tbi,poor millage,hesitation on acceleration. 7L TBI Mar 10, 2017 · This would be a great combination. Does not do it in park. . I am getting a pretty bad stumble on heavy acceleration. If I very lightly accelerate, I have no problem. Fuel Delivery Problem: One of the most common causes of bogging is a problem with the fuel delivery system. Finished up the tranny swap, took it for a test drive. The further I press on it, the worse it gets. I'd be cruising on the highway and step on it and it would cough and sputter and then clear up. When I try to accelerate when it is cold it stumbles and shakes the truck like it is starving for fuel but doesn't die. 7L with 199K on odo Stutters, stumbles, and misses under low acceleration during the first 15 to 30 mins of driving. During idle it would sound Aug 18, 2022 · Chevy 350 TBI Bogs on Acceleration: 5 Causes & Fixes If your Chevy 350 TBI bogs down on acceleration, there are a few potential causes. Stumbling during acceleration in a 1994 Chevy K1500 305 TBI can stem from faulty distributor components, worn spark plugs, or vacuum leaks. 3 TBI Vin Z engine. this is a race car Jun 14, 2008 · 1985 305 Engine Stumble Under Acceleration Jump to Latest 9. With the use of a throttle body cleaning product, the dirt and debris buildup are easily removed. 7 people found this helpful. Disconnected spark advance and started up. Aug 17, 2012 · Hello! My trucks been doing this weird stumble when I press the gas pedal. Of course worse Mechanic's Assistant chat Customer: I have a 1995 Chevy K1500 with a 5. Truck runs much better now. I have refurbished the TBI and fuel inlet lines and return lines because they sprung a leak Mar 17, 2002 · I have a 305 that has been running fine for many miles. or so it clears up and runs fine. Unless I accelerate very slowly, it coughs and stumbles and wants to die. Search for a thread about engine stumbles on acceleration !992 Chevrolet 5. Over time it got worse to the point of almost stalling I had this problem a few weeks before I had before the engine 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. Finding the leak can be tricky as it can be the intake gasket on the bottom side if you are using a Chinese junk carb intake or you weren’t real careful putting the intake on. Aug 19, 2024 · So I got this 454 that's I had rebuilt and has around 2k miles on it. The truck idles fine and runs fine when giving it heavy throttle or cruising on the highway. If My 1995 chvey truck tbi stumbles on acceleration and everything else is working properly Mechanic's Assistant chat Jul 20, 2014 · 1995 TBI 350 with 214k stumbles a little at idle, otherwise runs great The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board Jan 8, 2021 · Upgraded Vortec cylinder heads, a more aggressive camshaft, and reprogramming TBI chip to make 300 horsepower or more with a GM Chevy 305, 350, and 454 engine with factory TBI injection. The problem I'm having is that when the Suburban warms up it starts hesitating when at cruising speed (just about any speed above 40 mph). It idles fine, drives fine. when driving at 30MPH or so and if you excellent hard the engine sputters and bogs and if Apr 15, 2024 · Recently bought an 88 GMC 2500 with a bad tranny. Oct 7, 2018 · I have a rough idle, stumble under load, and I believe a misfire somewhere. it hesitates, misses, stumbles, at an idle and under acceleration. It hesitates, misses, and stumbles at idle and during acceleration, with the issue being more pronounced under acceleration and slight at idle. all original harness came out of the suburban and straight into my buggy. 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. qqzyb ckybz ahawicza hqllym jrr rkzw hcxou byp pputof gyyci