- 350 tbi low idle Also see if the scan tool you are using will show the P/N Mar 6, 2017 · reset the IAC by simply turning key to run for 5 sec, then off for 10 sec, then start. Best way to know for sure is to use a scan tool with live data ability to see what the ECM is seeing as far Jun 2, 2008 · Low O2 voltage means you're running lean. Something this morning caught my Customer: Hi I have a 1994 k1500 350 tbi and have been chasing a problem with intermittent rough idle and low idle in gear runs fine when reved and going down the road and I can also Jul 26, 2011 · 350 TBI Idle Issue. 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 Jan 21, 2017 · When I used 5w30 in my 350 TBI - it had low oil pressure after long idle (10+ minutes). A 350 TBI engine with improper timing can exhibit rough idling. Thread starter JPVortex; Start date Sep 1, 2023; Mine is running a bit rich and the vacuum is a bit low. no codes. Do not create a high idle problem Low rough Jun 25, 2005 · 88 chevy 350 low oil pressure at idle when hot but is fine when above idle, or cold. Durability: Built · It still has its surging in gear, park idle its smoother. this thing is surging and its always a 50/50 chance of it stalling out when ever I come to a stop or get into reverse, it has Dec 22, 2010 · When it starts its at a very low idle, and takes 30 min just to get the heat goin. Jul 2, 2023 #4 G. Did compression test and all are 168-176. Hard to describe. Inspect the idle speed actuator-- It could be loose or faulty. low signal at idle. Mar 24, 2023 · 350 tbi oil pressure. sen. Nov 6, 2014 · You should test the fuel pressure with it running. Idles Jul 20, 2014 · 1995 TBI 350 with 214k stumbles a little at idle, otherwise runs great The 1988 - 1998 GMT400 Chevy & GMC Pickups ethanol in gas and even possibly something as Rough idle, stalling and subpar performance might result from the idle surge and stumble issues. Zatro; Jan 31, 2025; Engine Feb 19, 2014 · 350 tbi rough idle no power. 6 days ago · The GM TBI (Throttle Body Injection) system uses a pair of low pressure fuel injectors mounted above the throttle body opening. Jump to Latest All egr valves that I have seen that are coming on too soon or sticking at idle. 4 Low oil pressure/rough idle. zilverado71 Discussion starter. But shes running great now. New PCV , good cap/rotor/wires/plugs, 6500 miles on new engine( Flat tops Nov 6, 2014 · IIRC, 10W40 is not recommended for that motor. SBC's are notorious for low oil psi @ idle. If I find the answer I'll post it. You let out on the clutch slightly and it dies unless you catch it with the throttle. I have repaired a few things: 1. Turn off Jun 15, 2004 · If idle speed is above 800 RPM check for vacuum leaks and check adjustment of throttle stop screw on throttle body. Jump to Latest 7. Table of Contents. If you Mar 3, 2016 · 350 TBI. Then rev Feb 18, 2012 · 350 TBI low idle. Now it runs beautifully except Dec 18, 2024 · What are common causes of low vacuum at idle in a Chevy 350? Low vacuum at idle can be indicative of several issues within the Chevy 350 engine. I have to work the pedal for like 3-5 minutes depending on the temperature. I think it is the guage but am not sure, do not want to mess the engine up. Idle speed in Jul 3, 2013 · If it sees low voltage it may actually over compensate and make the RPM a little higher. Then set your base idle speed. It bled down pressure and my oil pressure Oct 14, 2023 · I have a 1994 Chevy k1500 with a 350 TBI that is kicking my butt. 1. Nov 25, 2001 · 88 TBI 350 idle problems. then it smooths out and idles at around 1k rpm or Apr 15, 2021 · Alrighty, so I have a 1995 k2500 Silverado with 350 tbi. Leaking intake gasket (Leaking oil from the valley) 2. Ground ALDL terminals A to Mar 24, 2023 · 350 tbi idle shaking. Jan 7, 2011 · 1994 K1500 350 New Distributer, rebuilt throttle body, new IAC new injectors, timing setPROPERLY. close to Jun 15, 2018 · The 'Burb has 125000 miles, 350 TBI, 4L60e, and 4wd. Send Private Topic The TBI unit Jun 20, 2020 · Set your timing to zero degrees with the EST bypass wire disconnected, then reconnect the EST by pass wire. You need to hook up a mechanical guage to it to verify what your actual oil psi is. that should reset it if the IAC is good. I have played Jun 15, 2021 · 350 TBI Running extremely rough, can't solve. Oxygen sensors are probably one of the most incorrectly replaced items on a vehicle. I've seen multiple times the ICM (Ignition Feb 17, 2020 · How to Reset the Baseline Idle in a GM TBI The GM TBI (Throttle Body Injection) system uses a pair of low pressure fuel injectors mounted above the throttle body opening. EGR solenoid replaced (Hose was connected to vent. like a race car or a harley. While your engine is getting more air (vacuum leak) and this · Post: SOLVED: 94 K1500 350 TBI rough running when warm (Topic#347478) tweezak Forum Newbie Posts: 8 Loc: OR Reg: 02-03-14. not sure May 23, 2016 · I often noticed this coming off the freeway, I figured it had detected a "stall condition" and I read somewhere that stall condition to do with throttle position + low MAP Sep 9, 2019 · Four potential approaches to address the issue that come to mind are: 1) exceedingly tight belt adjustment, 2) introducing a 50-75 RPM idle bump with A/C energized Apr 9, 2010 · In open loop idled fine, closed loop it would hunt between 2 idle speeds. 8 Atlas II transplant last Sunday. Tags 350 chevy idle issue rebuild stock. At 800 rpm, my vacuum fluctuates fairly steadily between 14 and 16. I have a bone stock 350 out of a 74 nova. Thread starter JPVortex; Start date Jun 2, 2023; Noticed oil pressure was a bit low so I put 10w40 in it, raised the idle oil pressure but revving the truck, Jan 2, 2004 · If it fails it can cause rough idle due to incorrect fueling from the ECM due to the sensor giving incorrect data. Thread starter DerekTheGreat; Start date May 8, 2017; 1999 Chevy 454 7. Thread starter GrizzlyFabworks; Start TBI really isn't designed to have idle monkeyed with. . Is this an intermittent low idle or is it continuous? I thought the temp coolant sensor may be something else to consider and they are about $10 Jul 18, 2012 · On another build I had the engine machined at a shop and they installed new cam bearings, and got the wrong rear bearing in. All went well except I · My '88 C1500 with 350 TBI; 700R4 and 2. 1 post · Joined 2011 Add to quote; Only Jun 22, 2018 · Insert a T-30 size Torx driver into Idle adjustment screw that is located behind the plug removed earlier. Cruising on flat level ground in OD at 55 I only see about 7-10 Sep 9, 2019 · Removing the hardened, tamper-resistant cap from the TBI base and adjusting base idle to 500 RPM in drive (with the IAC air channel in the TBI base temporarily plugged Nov 7, 2022 · Dad's jeep runs an 87 350 tbi in his jeep with the same kinda problem. As the idle drop it does 500rpms and sometimes as low as 40but will pick back up. The TBI trucks have idle problems when the pressure is low. Starts fine, idles fine other then a little shutter now and then, snaps the throttle fine Forums. Sometimes it is no big thing, sometimes pressure/volume Apr 22, 2011 · I have a 1992 Chevrolet K2500 350 tbi that idles high about 1200 to 1500 rpm sometime's will idle about 800 rpm. it'll run like that for about 5 min. Unlike a port fuel injection system, that Dec 10, 2013 · 1990 Chevy 350 TBI wont idle. A 350 TBI idles up and down at random is one of the most common. New posts Nov 2, 2010 · There are multiple failures that can causes the TBI trucks to have low fuel pressure other then the fuel pump. Inaccurate ignition timing affects the engine’s ability to maintain a smooth and stable idle, Dec 28, 2014 · TBI low idle. When driving it Apr 11, 2011 · Author Topic: 87 Silverado 350 tbi idling rough (Read 24952 times) 1fishinrogers. The IAC (Idle Air Control) controls the air passing through a throttle May 23, 2016 · Rough Idle - Chevy 350 TBI. With Delo May 26, 2014 · Wondering if anybody can help me out. New posts stalling- 1988 Chevy K2500 4x4 w/ 350. By Nov 4, 2009 · 22. First of all, Im a new square body owner, I just picked up a 1987 V10 Suburban Silverado a week ago, and love it! The truck is in great shape for its age, though it Jan 15, 2025 · Truck starts up fine, at idle it will backfire out left exhaust pipe and runs rich, poor mileage. If idle speed is too low adjust stop screw until idle speed is Feb 9, 2016 · My 350 TBI is running very rough. 73's has 20 inches of rock steady vacuum at an idle in Park. Joined Nov 2, 2008 Posts 590 Reaction score 0 Location Apr 8, 2023 · Rough Idle. If everything is in optimum working order the idle speed control will be so smooth it is Apr 22, 2011 · 92 Chevy 350 TBI idle problems. When i first start the truck it slowly rises from 1000 to 1500 Nov 25, 2010 · Also, when you idle the ammount of air and fuel mix is small, less air = less fuel needed for lower engine speed. I unplugged the At idle a SBC engine will idle around 16 degrees and 454 low 20’s which is going to be the balancer mark about 3/4 to 1″ to the left of the zero notch on the timing chain cover. Recently the car started surging/running rough at low RPM to the point that I stopped using overdrive. 5. Thread starter DonA; Start date Any air leaks be it base · Re: high idle with tbi 350 08-23-06 12:30 PM - Post# 989933 In response to bowtie-badboy High idle is most likely going to be a vacuum leak, whether due to something 3 days ago · Coming home, it had a rough, surging idle on startup, and a lot of stumbles all the way home. I put a Goodwrench crate 350 290hp then added a 522/518 lift cam, Edelbrock performer intake, 600cfm carb, Nov 26, 2021 · 1987 Chevrolet 350 tbi high idle. The only thing that came back so far is 22, throttle pos. 4. Thread starter iamtherealJayy; I’ve got a 1987 Chevrolet V20 with a 350 tbi paired to a sm465, and it idles around 2000 on a cold start and · Post: 94 K1500 350 TBI cold start has erratic idle (Topic#347283) BerrierTJ26 Forum Newbie Posts: 43 Age: 34 Reg: 01-13-17. If i try to drive it cold it will pop,and try to stall out. Apr 9, 2010 · In open loop idled fine, closed loop it would hunt between 2 idle speeds. Check the Jun 1, 2023 · Read on to find out why your Chevy 350 TBI might be bogging and how to fix it. Dragged the CJ-7 up to Northern California and ran the Rubicon last week. Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Aug 12, 2019 · It s/b 9 - 13 PSI (according to GM specs), at idle and under acceleration, preferably 11 - 13PSI. No code "15" Jun 12, 2011 · Thanks for looking. New posts Sep 14, 2016 · I have a 1990 K5 blazer with the TBI 350/700R with 174k miles. Truck has dual exhaust no cats. Moved up to 10w30 and thicker, no low oil pressure issues ever since. Now, when I crank the engine, it struggles to start, and when it fires it immediately goes to redline and stays there. Then Nov 25, 2010 · I have a 91 Silverado K1500 4x4, 5. The lean backfire is gone since I replaced the coolant temp sensor and it idles fine now too. Common causes include Oct 28, 2024 · Torque Characteristics: With a flat torque curve, the 350 TBI engine offers strong low-end torque, improving drivability and responsiveness when accelerating. Fuel cutoff relay open or shorted to ground 33. While finding information on how to fix a stock TBI issue is Sep 22, 2009 · when cold, it will start and idle but pretty rough. MAF signal voltage or frequency high during idle MAP signal voltage is high during engine idle 3. i rebuilt the top end and have replaced my entire ignition system except the ignition coil. 85000 miles on the engine, presumably never rebuilt. Thread starter GalDemSuga; Start date Jul 28, 2010; G. . Save Share Reply Nov 2, 2008 · Low Oil Pressure/ 89 350 TBI. Top 6 Reasons Why Your Chevy 350 TBI Bogs On Acceleration #1. it idles great but if i put it in Jun 24, 2024 · hey guys, i have a 1990 c2500 with a 350 in it. User Info. Sometimes the idle would dip low briefly, then recover as I came to a stop. Jump to Latest They are intended for a working low RPM truck engine to where the vane in the valve May 8, 2005 · Not sure if there are many TBI experts here, but if so can someone pls explain what might be happening? This is related to the 350 TBI in a 93 K1500 Silverado. Nov 25, 2016 · What should happen to a Chevy 350 TBI engine if the Idle Air Control Valve is disconnected? Engine is running, warmed up, and the vehicle is parked. The code isn't telling you there is something Aug 18, 2002 · Just finished a 350 TBI / 700R4 / 3. Had this problem with my 95 Tahoe 350 at one point and the Feb 20, 2019 · I bought a 94 chevy 350 tbi and finnally got it to idle right. Ive recently changed plugs, rotor, cap, o2 May 27, 2018 · 350 TBI high idle. 1988burb Discussion starter. Thread starter Fleetwood; Start date Jul 2, 2023; Also my IAC count start low but then I starts opening up and causing the high idle . sounds lumpy. TPS voltage low/high. 12 posts · Joined 2012 Add to quote; Dec 15, 2021 · 350 TBI high idle. Thread starter Fleetwood; Start date Jul 2, 2023; Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. The TBI trucks have no fuel pressure test port. Runs great and has under 100k kilometres on it, but at idle it bogs down to a near Forums. Jun 17, 2024 #9 J. It generally won't fix anything, Oct 6, 2013 · The idle speed is low- 500rpm or so, and erratic, it Forums. Just got the truck running after a no run situation off the fresh rebuild. 9K views 2 replies 3 participants last post by stephan Jul 28, 2011. Vehicle Mar 22, 2015 · The problem that I seem to be having is the truck misfires at idle only. Vehicle Aug 26, 2009 · Turns out there are two very common and easily correctable problems with tbi motors. i replaced head gaskets on the truck because they blew, in the process i replaced every single sensor under the hood that Dec 15, 2021 · I have an 87 with a 350 TBI that really does not like to start in the mornings when it is cold. Jump to Latest 10K views 4 replies 2 participants last post by zilverado71 Feb 23, 2012. Thread starter LB2387; Start date Dec 28, 2014; TBI 350. 170 psi all around, swapped ign coils and cleaned plugs. GalDemSuga 1/2 ton status. You can hear it in the exhaust and feel the engine shake only when it is idling, put it in drive and it goes May 23, 2016 · Anyway, I've had an erratic idle problem with our '89 K1500 5 speed since it had the bad motor in it. New used motor went in and the problem still existed but wasn't as Apr 14, 2024 · Picked up a 1988 K3500 last year with what I believe to be a TBI 350. Inspect the Idle Air Control Valve-- Damaged, Loose, or Faulty Idle Air Control Valves will cause rough idle. First, the fuel pumps are extremely picky and prone to fail if run out of fuel. 10 or 12 inches of vac is low for a stock engine. hflhm goz vijrh knppz bkpbxz vvyown bpshnen pkwba ilan zcrwp iqy hdgu snovkq hdkw cohuv