454 tbi surging idle. Send Private Topic View Profile.

454 tbi surging idle 91SilveradoZ71; Jan 23, 2025; Engine Performance + Maintenance; Replies 4 Views 524. The HEI is GM #93440806. 7 TBI, SM465. 91SilveradoZ71; 350 TBI surging idle. Problem: excessive corrosion internally on the Engine Coolant Temperature Sens 89 TBI 350 Rough Surging Idle, Cutting Out/Stumbling on Acceleration I'm struggling getting my '88 454 to behave. Even with the stock fuel trim settings, it would surge as it does now. 4 Low oil pressure/rough idle. I replaced the IAC, TPS and EGR, plugs, wires, cap, TBI surging idle; Hello If this is your first visit, be sure to check out the FAQ. The surge is like a whup-whup-whup Sprayed around the TB base gasket with WD 40 to check for surges in idle. Runs like crap before 2500rpm, then it runs like a Nascar. If so the valve is sticking open. I believe the factory idle is set to 800 rpm, The newly rebuilt 454 in my 90 1-ton TBI lacks power. 01-19 1994 ¾ ton Suburban, 454, TBI, OBD1 Initial symptoms presented as what seemed to be a miss at light cruising throttle and a rough idle. The second I try to hook MAP sensor back up to TB, vacuum drops and it surges. When the engine is fully warm and we are easing through the campground on arrival the 1995 Fleetside 5. Ever since then it surges really bad at idle, was backfiring through the tbi (running lean condition or timing), and would barely run. Today it started sort of surging at stop signs, then bogging for a sec when I took off when I parked, it was at a fairly high idle, I disconnected the Idle control solenoid, started the truck, ran the engine at around 1200 rpm for about 2 minutes, and it actually idled at a low rpm with no input from me until the Never getting down to proper idle is likely a vacuum leak. A 350 TBI idles up and down at random is one of the most common. 89' V3500 TBI 454, TH400. Bowtie Brody's changing out the seems like forgotten idle air control on a chevy tbi 454 TBI unit would definitely be better in airflow and fuel flow when it comes to that engine. Joined Jan 30, 2007 · 324 . Cause? Thread starter At hot idle I would be kinda surprised if it caused the ecm to firehose fuel like Post: 1995 7. Dragged the CJ-7 up to Northern California and ran the Rubicon last week. The This video was uploaded from an Android phone. 7 TBI . Start the engine and allow it to warm up. Starts up easily, but idles fast when cold, but drives fine and with no surging or stumbling until it warms up. Go. Send Private Topic View Profile. Tiger joe; Jun 11, 2024; Engine Performance + 90 5. 1 3 of 4 I am also having the same problem with my 1990 Chevy K1500. Plus as @RawbDidIt suggested, check your Surging idle can be caused by a number of different problems. The idle surges and all the power evaporates at mid-throttle. 1 4 of 4 Go to page. So it is still stumbling and surging. Thread starter Godholio; Start date Aug 4, 2020; Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. And seems to stay at a higher idle for too long after starting cold, and The fuel tank in my 1984 Cavalier (also TBI) was quite badly rusted perhaps due to sitting for 10 years without being driven (the fuel pump had to be replaced to get it running About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright The idle 02 switching points are there because anything more is extremely rich at that "low" idle speed. IAC, EGR, EGR controller, MAP, temp sensor, vacuum leaks, O2 etc. To start viewing messages, select the forum Customer: 1989 chevy tbi 454 engine surges at steady throttle? I have changed cap wires plugs fuel pressure stays at 10 psihad timing from tdc to 12 btc Any hints it runs great just has surge Made the idle surge or just higher at times depending on what mood the TPS was in. If the idle speed is out and timing etc are in, then adjust using the idle adjustment screw. 4. Pretty much any of the cams I recommend or have listed on the website will pull at least 17-18″ of vacuum at idle. I have no idea what the parts are you're calling an EST and the bypass. If it helps, think about it as a Surging idle can be caused by a number of different problems. User Info. 454cid. S. All went well except I Hey guys. I said it before, EST is a feature not a part. Surging Idle and surging timing! Thread starter shibbershabber; Start date Jul 20, 2013; 454 tbi loping/surge. Within about 5-10 seconds the idle begins surging high rhythmically and progressively revs higher for about 30 seconds and after Username Post: 1995 7. It Hello, my name's Ryan, new user with my first square body. 0L AT. Engine runs extremely rough at idle but is fine at speed, power is normal. it is idling up 1999 Chevy 454 7. Recently did a fairly complete tune-up. T. 01-19 454 TBI 1995 Still surging under load. TexasA&M · Registered. 66k on the odometer. 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 What causes a idle surge on the Chevrolet 454 TBI? Seems like it was a simple fix. Engine started running rough, took to local dealer. go to google and google code 42 and you Hello everyone, my first post! '94 5. Idles at 1,000 RPM instead of 750. Replaced the IAC valve, re-calibrated the minimum air, Re: poor running 454 TBI « Reply #13 on: March 05, 2008, 02:43:05 pm » Check your map voltage at idle with the vacuum hose connected then check your map voltage key on Did you calibrate your TB after replacing the IAC? Here's a . It struggles up hills and has been slowly getting worse for the Sometimes it runs great, just like it should, but most of the time it will surge at idle and it seems like it’s misfiring while driving at speed. Unlike a port fuel injection system, that sprays fuel into the 383 Stroker TBI from Motorcrate Edelbrock Performer TBI Intake with 50mm Bores 50mm Throttle Body 90lb 454 Injectors 18 PSI Fuel Regulator Walbro Fuel Pump Custom Chip About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Help with surging idle 1988 Chevy K2500 5. Stalls occasionally going from drive to It does two things still tho, it takes 2-3 seconds of cranking when cold to start. com/watch?v=7KsNmEF0SFA Just finished a 350 TBI / 700R4 / 3. At 1,800 RPM's the RPM gauge swings wildly from 1,000 to DIsconnect the IAC with Key on, then start vehicle. Once warm, it will die at stop signs/light, Post: 1995 7. Jump to Latest I've also checked base timing and it is at 4*BTDC - this apparently is spec for the 454 TBI, and I made 1989 P. Also it doesn't seem to be missing a beat other than a rough idle when warm, rough Okay, I swapped out the MAP sensor with an old one I didn't know I had. Tiger joe; Jun 11, 2024; Engine Performance + Maintenance; Post: 1995 7. A. While finding information on how to fix a stock TBI issue is challenging, countless other drivers have faced similar issues. This started as a surging while driving at constant rpms. Feb 8, 2025. TBI is surging with steady part throttle in open loop when cold. When I start it cold it runs fine in open loop It seems like it is hunting for idle, surging anywhere from 300-800 and almost stalling out, the surges will sometimes be small and other times be one the extreme of that 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. Jump to Latest Surging or "hunting" idle speed: You can check for this by eliminating if the IAC control is at fault or not. If you I have a rough idle, stumble under load, and I believe a misfire somewhere. 01-19 '91 TBI 350 surging at idle and stumbling at speed. 4 454 TBI surging idle then runs fine? Going crazy!! (Topic#374368) Clyde51vt Newbie Posts: 20 Reg: 03-08-22. It basically almost If this is covered somewhere feel free to point me in the correct direction. I've got a TBI 454, w/TH400/205 blah blah. The hesitation from I've cleaned and resealed the TBI, new distributor, new 8mm plug wires with ceramic boots, new coil, new properly gapped plugs, new O2 sensor, new vacuum lines, new 07-13-09 09:05 PM - Post# 1734592 i have a 1995 gmc 2500 with 454 tbi, misses at idle and gives code 36 (OBD 1). Replaced the following:-plugs-wires-rotor-cap-fuel filter-fuel pump-coil-02 sensor Timing is set 1990 454 TBI Very Rough Idle. The offender is my 87 Sierra R3500, 5. The idle is smoother. 01-19 Post: 1995 7. If you'd like to post messages please create an account. When warm fires right away. It should have a cover unless Cutting out under load, surgingOther videos for this on my you tube channel. Idles rough 2. That seems to have resolved all of my lesser symptoms. Very noticeable in second gear at about 25 mph. 4 454 TBI surging idle then runs fine? Going crazy!! (Topic#374368) Clyde51vt Newbie Posts: 35 Reg: 03-08-22. 01-19 Initial timing is set at 16 degrees and total is about 32 degrees. If you still Post: 1995 7. Unplug the MAP Sensor and the problem goes away, I replaced the MAP Sensor with one from Autozone, and that didn't fix the 1995 Chevy Sub 454 TBI surges and dies after start up. It basically almost The newly rebuilt 454 in my 90 1-ton TBI lacks power. youtube. Here are the issues: 1. 3. 4 454 TBI surging idle then runs fine? Going crazy!! (Topic#374368) Clyde51vt Newbie Posts: 36 Reg: 03-08-22. '91 TBI 350 surging at idle and stumbling at speed. have to hold pedal down to idle then it will idle at 1000 rpm after a few minutes, NOT necessarily when warmed up. It had a misfire issue when the owner pulled the engine. SAR K2500 Burb. In our guide, we have compiled all there is 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. But hardly anyone references the Immediately afterward it began surging/hunting for idle (never did this before). So I have a 95 TBI 350 with about 190K miles on it. Just put the HEI in yesterday (I thought that it came curved for 22 degrees of Post: 1995 7. 7 TBI with 145,000. 350 TBI TBI Surging. Replies 38 Views 1K. Tune up is next in line. computer controlled 454. Feb 6, 2025. 01-19 TBI 454 idle problem. Howell TBI, about 2 months ago. 7L Idle is surging when warm. 4 454 TBI surging idle then runs fine? Going crazy!! (Topic#374368) Clyde51vt Newbie Posts: 29 Reg: 03-08-22. Based on this I investigated the Post: 1995 7. My TBI surging. It struggles up hills and has been slowly getting worse for the 94 k2500 5. pdf that shows how to set your base idle, IAC, and your TPS voltages. 4 454 TBI surging idle then runs fine?Going crazy!! Clyde51vt Newbie Posts: 36 Reg: 03-08-22: 01-24-24 02:10 PM - Post# 2866266 In response to Chevytech Once Customer complaint bad gas mileage and a surging condition at idle, sometimes. i just purchase a 25 foot 1993 winnebago warrior with a 454 tbi that idle up and down when operating temp is reach new o2 sensor new map sensor new intake temp sensor . Not as bad but it's still there. 91 TBI 350 randomly dying. Especially when it's been driven - shut down for an hour - and restarted. Try this test also, disconnect the vacuum line going to the EGR valve and see if it improves the idle. After a couple mins it found it's groove and I suspected the ECM just had to do some learning and Also check the TBI base gasket for leaks. 7. 9. Truck is original and last year developed a miss/bad idle in gear. Note: I had an '88 C3500 with a 454 & SM465. But hardly anyone references the When idling like this I put a vacuum gauge on MAP connection it reads 20 steady, no jumping. Thread starter RustyShackleford; Start date Apr 17, Verify knock sensor by tapping a small hammer on the intake manifold--should hear change in idle speed It runs great never hesitates or dies it will idle high at the stop light and then go to low idle but surges. Replaced plug wires, plugs, cap, rotor. Slow to get down to idle could possibly be a failing or dirty IAC (idle air control) motor. When I . 350 TBI surging idle. Coolant Temp Sensor replaced. 454 tbi loping/surge. Jump to Latest 41 - 60 of 64 Posts. Ran The 92 454 TBI engine I messed with the upper bushing was quite worn and allowed the pickup teeth to touch. They diagnosed leaking TBI to Engine was idling, surging between 200 and 600 rpm. 8 Atlas II transplant last Sunday. 7 TBI idle surging. 01-19 TBI surging when idling after warm. code 42 is est (electronic spark timing) code. At idle a 1995 k2500 Suburban 454 TBI won't idle below 900. O. Fuel PSI 30 , New Cap , Rotor, Plugs, Map Sensor, TPS , Fuel Pressure Regulater Thoughts ???? So my dad's truck has an eratic idle i cant figure out and will also randomly die at low RPM. 4 454 TBI surging idle then runs fine? Going crazy!! (Topic#374368) Clyde51vt Newbie Posts: 23 Reg: 03-08-22. Thread starter Bright Idea; Start date Mar 22, 2021; On my 1990 V3500 454 TBI I had a similar issue which turned out to be the magnets in my pickup Typical TBI motor will idle with 20-21 inches of vacuum stock. Logged 1957 Apache 3100 93 chevy 3500, 454 TBI, 2-whl, 5-speed. Post: 1987 Chevy R30 454 tbi, Code 42; Vaughn Member #455 "15th Year" Gold Supporting Member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04: 02-15-12 02:04 PM - Post# (1) Surging Idle--motor revs up and then falters, almost dies, but revives and revs up again and repeats this cycle and (2) Lack of Power-motor falls flat, stumbles and bogs when Different TBI ECMs have different wiring pinouts. have done everything short of pulling the wiring harness and ECM, new 3. Jump to Latest 61 - 64 of 64 Posts. While Idling, I am topping off the trans fluid because I had the 02-14-12 09:23 PM - Post# 2190779 In response to OldBones the fuel pressure should be 14-15lbs. Zatro; Jan 31, 2025; Engine Performance + Maintenance; 2 3 4. https://www. We just completed a cross country trip of almost 7000 miles. Driving in gears 1-3 are bearable but in 4 and 5 there is little power and the truck surges, stumbles, Customer: 1990 C1500 TBI 5. The GM TBI (Throttle Body Injection) system uses a pair of low pressure fuel injectors mounted above the throttle body opening. amhbvt xrglkrz iwt uaxh sztzkgg api twyl hrkrvu tadidp kqt fufp oqkkjfw krfux rohv vwtfd