Chevy tbi runs rich. ICM was replaced and still happens.

Chevy tbi runs rich _____ Greetings everyone, thanks in advance for anyone who replies, i have a problem with my 1990 chevy caprice 305 tbi, its running rich i removed all the spark plugs and they're all black so with my research i figured that its running rich. The ignition leads are Magnecor and are new. 1988 Chevy S10 4. it is not showing any codes. Is unplugging 1 of the injectors actually allowing MORE useable fuel into the intake and therefore it New to the forum, my 350 runs very rich at idle. It runs awful until up to operating temp and still lacks power then. Joined Jun 15, 2021 Posts 3 Reaction score 0 73-87 Chevy _ GMC Trucks » Newbie; 350 TBI Runs Rough « on: September 21, 2016, 10:22:09 pm » So I have an 87 Silverado half ton. None. Go. Oct 27, 2024. Removed a mile of wire, set fuel pressure, throw tbi in trash can, set timing, and boom I had a problem with mine running too RICH But I finally took the time to eliminate the head to exhaust manifold leaks (drove me crazy!) and it seems as it was running rich to compensate for a seemingly bad reading at the O2 sensor. The TBI 454 in my 1990 GMC R3500 Crew Cab runs very rich when it's cold. Feb 2, 2024 ive been talking to bd about this issue, but i think i have it kind of figured out for the most part. Home. ICM was replaced and still happens. While running I can unplug one of the injectors (doesn't matter The O2 sensor will not resovle or compensate for, bad sensors, leaky injectors/seals, manifold vacuum leaks, excessive fuel pressure or ignition issues all of which Hello I have a 1995 Chevy K1500 5. When I put it back in park after driving it for a while, it shoots up to around 1600 rpm and slowly comes back down. winter or summer. I tried checking the fuel pressure before rebuilding the TBI but the crappy harbor freight TBI adapter in the kit leaked everywhere. '92 C1500 5. Post: 1987 Burban TBI SBC 350 5. Temp sensor, map, and tps all appear functional, checked with scan tool. 1 ©2003-2006 InteractivePHP, Inc. Truck isn’t running rich, CEL is off but the idle is rough. 7 tbi runs rough cold and. 7 vortec. MTBLAZER89 3/4 ton status. I tried a different MAP sensor, Ignition control module, a different TBI and the engine still is running very ruff and rich. This version appears to have A. Forums. It was running rich before the rebuild and is still running rich. 87 tbi 350 popping at idle and running rich. I did a rebuild of motor, cleaned gas tank, new pump and sending unit and new filter. I do not seem to have as much power as I should. M. Fine at cruise Idles very smooth. My truck is running rich. I have a 1990 350 tbi that runs great cold. Hello. I replaced the CTS, but it has not made a difference. It’s sluggish and should have more power. 1 of 2 Go to page. The power is really bad though. 5% CO Have not looked at plugs, but runs smooth at idle and cruise There was a code 15 prior to Spring inside the FPR was good, not broken. 7. The tach would still twitch at times, and the truck was now As the engine is warming up lots of parts are heating up unevenly. It's not checking for a rich condition yet. then after messing with it its seams to be running better (no stalls and no black soot) its still reading rich but then it will adjust and read lean then adjust and read rich again. BobbyBigRigger; Sep 23, 2024; Engine Performance + Maintenance; 2 3. 7 TBI running after 10 years of sitting inside. only problem is when pulling a. It runs through gass a little fast for my liking. But in this case the check engine light comes on. 6. Also when in gear when you let off the throttle it stays reved up for a extra second or two. I'm a decent mechanic and have worked on these TBI engines quite a bit in the Author Topic: TBI running rich at 25mph (Read 15568 times) 1MCP7. I have replaced the MAP sensor, Egr valve, temp sensor, distributor, rebuilt tbi, and regulator. If so , locate the map sensor and pull the vacuum line from the sensor, engine should run fuel rich and have a noticeable change the way it sounds. Thread starter GrizzlyFabworks; Start date Jul 28, 2021; Tags engine idle management problem rough runs tbi G. After warms up it either dies or will not restart after shut down. The engine seems to be running rich as the plugs are black and the exhaust is black, it idles for a bit and the idle drops and sometimes comes back, but usually stalls. There is no SES on and the light is functional. Put a muffler or an exhaust pipe that is at least a foot or more in length on the back of the collector to eliminate the contamination of the exhaust stream out of the collector. It's done this since I got it about a year ago, but I really haven't used the truck very much. 11 posi, 4. Jul 31, 2008 #1 My TBI 454 has been running rough. 7l vortec is running rich, very very rich. 3L TBI Rough Idle (Running Very rich?) troubleshooting Archived post. You can tell its running rich by the strong fuel smell coming from the exhaust. Answered by Gary in 29 mins 9 years ago. Rebuilt TBI, new Ok so I have an 87 gmc tbi the truck runs great when the motors not up to temp but once up to 180 it runs like a dog with no power it failed the smog check due to it is there a sensor that could be bad that is causing this to happen. b. It also is using alot of fuel. 3 that runs very rough and does not idle properly Mechanic's Assistant: How many miles are on the car? Have you checked the spark plugs? Customer: New spark plugs, new distributor, new plug leads, new map, new idle air control valve and new injectors Mechanic's Assistant: What is the model of your '91 Chevy? I have a 91 S10 Blazer 2WD that is running super rich, strong smell from tailpipe, bad mpg. p. Sent from my Nexus 4 using Tapatalk 2 I have a 92' Chevy 350 TBI engine in my Jeep and for the past year it keeps running rich. 23 gears 92,000 miles Email Report someotherguy Senior Moderator Posts: 29848 My 1988 Chevrolet V30 with the 454 t. 10-02-17 09:07 PM - Post# 2709587 350 tbi running rich. 7 tbi engine with the GM#1227747 ECM. If that is My 91 original 305 TBI injected camaro, currently running too rich, stalling while flooring it, backfires on the exhaust and intake mouth, how can I make it run leaner, thanks:) But a TBI chevy with a carb on it is absolute crap because Running Rich, Code 45, TBI 454 ***FIXED*** Thread starter MTBLAZER89; Start date Jul 31, 2008; 1; 2; Next. Started and ran a ton better! I have my fuel pressure at the TBI between 12-16 psi. Fully rebuilt block,heads,and tbi. It just means you need to re-tune and IF you are running rich: Either your injectors are stuck open (usually an ECM fault), the fuel pressure is too high, or the ECM is getting incorrect signals from one of the sensors. Make sure it has FULL vacuum at idle , check it with a gauge if needed. Before it reaches operating temperature it runs in Open Loop, using lookup tables to set air/fuel ratios, etc. Spark plugs are black and sooty. My 95 with the TBI 350 is running rich. This truck has a good motor but it lacks power all the time not like barely moves but it TBI 350 running rich The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board Register or Log In To '84 chevy half ton short box 2wd, 67,000 actual miles '03 chevy 1500 HD crew cab 4x4 standard box, 6. 1999 chevy 454 tbi in a motorhome. 7 TBI Engine is running really really rich. I replaced every sensor and electronic component, rebuilt entire TB including No leaks, but still runs way rich. Idle surges, blueish/white smoke on start up. The truck has new wires, cap/rotor, plugs. 10-01-13 06:15 AM - Post# 2386990 Hi there - I am struggling to figure out why my 99 Chevy K3500 with a 5. 7 TBI runs rich, hesitates The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board Register or Log In To remove these '84 chevy half ton short box 2wd, 67,000 actual miles '03 chevy 1500 HD crew It is also worth mentioning that when I would crank the engine, the tach on the dash would go up to 5k rpms and then twitch around (the truck was not running). A heated O2 sensor can run with the O2 sensor located in the header collector, but there has to be more of an exhaust system bolted to the collector otherwise the O2 sensor will not read the exhaust stream correctly. Injector flow is great, forgot to mention about a month ago I completely rebuild the TBI unit, did not help the cold running at all. Let cool off a couple hours and starts back up and runs fine until it's hot again, then is dead until it cools off. Tags They were all rich probably because I had been running it in open loop. At the 15mph test it passes good at 25 it fails even adjusting timing didn't help it pass like last year. Im lucky enough to have a friend with a perfectly running 91 tbi 350 truck he doesn’t use much that he loaned me and I spent the day Post: 93 4. 3 S/T truck have TBI. F The distributor is a MSD with new cap and rotor. 69 Chevy stepside, 358/T350, 4. I have replaced EGR, coolant temp sensor, grounds, idle air control valve, manifold gaskets. Takes longer to I just got a 1990 5. sensor, o2 sensor and the computer does not bring up any codes. is running way too rich, especially at idle as it smokes brown + smells really gassy, so my question is what could cause this and how would I go about fixing it? Edit: I've thoroughly cleaned the throttle body, replaced the 02 sensor, and have replaced TBI Running rich. 87 TBI 350 runs rich, stalls, stumbles, slight backfire out exhaust The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board 1951 Chevy Sedan Delivery 2004 Chevy Tahoe Z71 2011 Harley Davidson Street Glide 2018 My son's has a 95 S-10. 1987. OWNER and Administrator; Administrator; Senior Member; Posts: 18421; 1993 5. But seems to be running rich and missing a little. Fresh rebuild no leaks. Might just carb swap it. I got a throttle body rebuild kit and changed all the gaskets in the injector assembly and what not. i. My engine is running to lean, or is backfiring on acceleration. 5. I am getting a sag when I accelerate. The IAC is definitely something I will check out. 4. So the o2 sensor couldn't be thrown off from getting to much fresh air? If you run the headers open, with the O2 sensor in the collector, it will probably run way too rich because the exhaust gas stream will interact with the surrounding air at the end of the open collector, causing the O2 sensor reading to be off (it will tell the ECM it is way too lean, so the injectors will go full rich). The distributor can't cause the engine to run rich. 7L TBI truck 172k miles 6" Procomp lift 35" Nitto tires on 20" rims stock gearing auto transmission, I have been trying to fix this issue for a while I just got a 1990 5. This gives max fuel pressure and a rich condition. Execution time: 0. If you run the headers open, with the O2 sensor in the collector, it will probably run way too rich because the exhaust gas stream will interact with the surrounding air at the end of the open collector, causing the O2 sensor reading to be off (it will tell the ECM it is way too lean, so the injectors will go full rich). 5/4 drop, rallys, poboy driver primer is finer (350 motor/TBI) runs rich on cold starts. GrizzlyFabworks Newbie. Another thing to look at would be the IAC (idle air control) valve. I've had a TBI 350 before, but it always ran perfectly, so I'm not too up on how to troubleshoot these. R10. 1 2 3. Running with stock programming with a low idle speed setting combined with the fact the chip is designed for 20-21″ of vacuum at that idle rpm with a cam upgrade which typically drops the vacuum to 18″ or less will cause the motor to run too rich which will spawn a high idle speed where the motor will then lean out and rpm drops and repeat. Jump to Latest 9. Replies 28 Views 3K. Then hook the injectors back up and start normally. TBI running rich. or converters. 5K views 42 replies Runs rich when cold, sometimes wants to die. Main Index » Forum Index » Trucks-Vans-SUV » 1973-1987 Fullsize Trucks, Vans, 1973-1991 Blazers, Suburbans » TBI running rich FusionBB™ Version 2. It runs rich , and when on the highway at 65-70 it sputters and you have to give it more gass to get it to smooth out. I have replaced the m. No leaks, but still runs way rich. Post: 5. 3 Running Super Rich (Topic#152542) Cameo deuce Member Posts: 111 Loc: ABQ---NM Reg: 07-23-06. So my tbi 350 was running a bit lean and has been having a little missfire here and there so I decided to try the vortec pump and it ran rich with the vortec pump which makes me think my fuel 12-14-22 11:32 AM - Post# 2851251 I am building a 46 chevy truck on an S10 frame with a 1989 chevy 5. His original injectors Chevy Forums FREE technical assistance for your restoration and repair. Replies 48 Views 3K. I have a 1990 chevy 350 tbi that runs rich. New posts Search forums. If Has ran rough for several years. It sat for 5 years, till I ran it through emmisions June Hello everyone, I am a 17 year old with a 2001 GMC Sierra SL. So rich that you smell like gas after you drive it! It doesn't miss and Idles really well for how much fuel its dumping. The issue I seem to have is its running rich, loads up with gas and stalls out. a. I could be wrong here but I believe those O2 simulators are only for the vortec The new exhaust does not have O2 Sen. 7 350 TBI. I gave it a full tune up, checked fuses and did pretty much all the things the former owner should have been doing all along. Could it possibly be the temp sensor for the ECM - giving it a false reading and the computer is feeding it more gas than it It's a common problem with TBI engines. 030 and I also got around 180 psi of compression across all one thing you could do that only really aaffect idle is to unscrew the big IAC motor from the side of the TBI unit and get can of carb spray cleaner and spray the crap out of the pintle end and spring on the end of the IAC motor assembly and blast it off with compresseed air and measure from mounting flange out to end of the pintle of it and make sure is 1-1/8" or less Customer: 1991 3500 with tbi, runs rich and eating alot of gas, replaced the map sensor, cts and the idle control. Use a heated O2 sensor that has 3 or 4 wires for headers, two of which will be white. However, once warm the motor runs fine, except that the RPM takes a little longer than usual to drop down Running extremely rich is the problem I’m trying to solve, so far I’ve replaced coolant sensor, heated oxygen sensor, 3 different map sensors, fuel pressure regulator and rebuilt the throttle body. I have changed the distributor cap, rotor, wires, plugs, fuel I have a 1987 350 tbi truck that runs a little weird. it is running good strong and clean Chevy tech what is timing for this truck? By the way the coolant sensor was OK and all your help is greatly appreciated 2. 7 350 TBI 4L60-E 3. 5 TPS Ive got a 94 chevy k1500 305 with tbi that has been stumbling (or choking) on acceleration. 8. 7 TBI running rich when warm. Runs great, passes smog. scott2093. Is it running closed or open loop? Open loop will cause a rich running problem. Truck has dual exhaust no cats. chairmnofthboard. A non-heated O2 sensor needs to be within a foot of the exhaust ports. I have replaced the spark plugs and wires, fuel injectors, Coils, Mass Flow Sensor, Throttle body and the ECM. Did compression test and all are 168-176. Hello, I have a 1988 Chevy S10 Blazer with the VIN Z 4. It dose not throw any Chevy. Re: TBI running richHelp!! « Reply #3 on: January 25, 2015, 06:08:41 pm » Check vacuum leak or the vacuum line from back of tb to map sensor or possible bad map Tbi running lean and rich. 3/87GMC. I have one dumb question, would old plug wires make it seem like it is running rich like maybe there is a slight miss and a cylinder is If your chevy gm tbi is running rich this will help you trouble shoot it and fix itDon't Forget to Subscribe today for more fact or fiction, diy ,how to car Chevy Forums FREE technical assistance for your restoration and repair. I did all the assembly afterwards, clearances of everything seem to check out for the most part. Also new Coolant sensors, oil pressure sending unit. I have replaced temperature sensor, O2 sensor (went with heated), egr valve and solenoid, plugs, wires cap and rotor. I used my Innova scan tool to test the TPS and it is giving back the correct throttle percentages. Engine was rebuilt to factory specs but with factory-style roller cam instead of the original flat tappet 1991 Chevy Step Van 454 TBI Emissions running rich at idle. no codes. 222 posts · Joined 2002 Add to quote; Only show this user #1 · Dec 16, 2008. I've verified all of the normal things that may cause such as the map sensor, ECT. The truck then would start, but would not run well at all. Surges at idle, sometimes dies. thundrecougar New Reader 9/8/20 4:23 p. Remember now, since it has been here I can say that the engine is and has been running RICH, very RICH. Truck ran fine before rebuild, aside from at end of life due to age. this engine came from a junkyard and it looked rebuilt. It had been sitting for two years or so, and the second time Customer: Hello, I have a 1991 Chevy Blazer TBI 4. Unless its 90 deg or more outside it will run at ~185 deg. Not low enough to explain the problem. 3L TBI - Idle troubles getting the rest of the way to work. Recently my truck had been running rich. After replacing thermal sensor and injectors, it's down to 2-2. 1993 K1500 running rich (Topic#273969) THePaRaSiTE5771 Forum Newbie Posts: 5 Reg: 12-24-11. Doesn't really want to pull itself in overdrive. The TBI engines might run better with a restrictive exhaust because they were tuned with it so they go lean with a free flowing exhaust. I don't know where to look next. 1993 5. Thread starter Fleet89TBI; Start date Apr 6, I have a 95 Chevy Suburban 5. NO codes or SES. The truck runs rich enough at idle to sound like a 454 Chevelle with a hot cam. Pulls fine for a while at I have a 1990 chevy 1500 running rich. I have a 1994 chevy 350 it's running realy rich I thing I can smell gas out the tailpipe and there is black smoke and black dust over my exhaust tips Forums. A forum community dedicated to Chevy Astro and GMC Safari owners and Ihave a 1990 chevy 1500 running rich. i have a tbi 350 out of a 90 suburban in my jeep. TBI Chevy running rich. now we know you have a TBI system. When its cold, like 0, it takes longer to reach the rich stage, but its like clock work. 0L 03-19-2007, 11:19 AM #4: HuggerCST Chevy Tbi 350 lean -solved. Any Help? 1989 Chevy K1500 5. This is with a Griffin radiator and a stock clutch fan with no shroud and a 195 deg thermostat. The car had been in garage for 2 years, because last owner fried the transmission. 7 TBI. 7 TBI running rich, finally bugging me 01-22-05 03:47 AM - Post# 605493 In response to someotherguy Hey Richard. Captkaos. Newbie; Posts: 44; 75s my baby; 1975 Chevy Scottsdale 4wd swb silver slug 350 tbi 1987 GMC Sierra 4wd lwb 350 stock replacement. 7 TBI Runs rough on cold start (Topic#314297) ahhlicks Forum Newbie Posts: 10 Reg: 07-31-14. Jump to Latest I managed to get a 1992 S-10 Blazer with TBI, relatively low mileage, overall condition pretty good. A coil is on the way as well. all original harness came out of the suburban and straight into my buggy. I would appreciate any help. Also new Coolant If you have a failing fuel pump (super common for gm, it seems), are you getting enough fuel pressure to work well with both injectors? Is unplugging 1 of the injectors actually allowing MORE useable fuel into the I have a 92 tbi 350 that runs rich. While running I can unplug one of the injectors (doesn't matter which) and the truck will run normal for about 25-30 seconds before leaning out and dying. Truck runs and drives fine when cold and at operating temperature, when I shut it off and go to start it again after an hour or two it will give me a hard time starting, and when it does the idle is very choppy and sometimes stalls. They have two sensors: One for the gauge located in the intake, and one for the ECM located in the head behind No. devildogcummins; Jan 15, 2025; Engine & Performance; 2 3 4. Customer: I have a 89 chevy tbi that cranks from a cold start and runs good until it warms, then runs rough and stalls everytime. Jump to Latest A forum community dedicated to GMC and Chevy full size owners and enthusiasts. I get parts by calling it a G30 van. 350 tbi. Send Private Topic View Profile. Jump to Latest 82K views 33 replies 15 participants last post by lmiller Dec 2, 2019. Start it cold, wait 15 seconds of so and it goes rich and starts bogging down and sputtering. General Motors master tech from friendly Manitoba. Newbie; Posts: 6; Newbie; New member here looking for some help with 350 TBI running rich « on: August 10, 2015, 09:13:56 PM Chevy GMC tbi engine flooding hesitation smoking running rich running bad diagnose and fix 1994 K2500 Cheyenne 5. Sprayed the vacuum lines, TBI to manifold flange and all along the intake for vacuum leaks. Recently, I tried swapping a few of the common sensors like the tps, map and o2 sensors with some good used ones I had laying around, but it really didn't make much difference if any. The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board: TBI 454 running rich '93 chevy van w/ v-8 parked all winter was running good for 20 miles then started running rich upon acceleration, ran ok down the highway and would idle ok, just very rich when you took off. Takes longer to crank than it should. . Thread starter MrobsMan; Start date Oct 3, 2023; Joined Jul 21, 2021 Messages 74 Reaction score 37 Location Indiana. Starts and runs/idles rough until you accellerate some the it smooths out and runs like it should. I have a 1989 Chevy sprint motorhome 350 cu 2bbl tbi. I can keep it running with the gas pedal but when i let off it stalls everytime. Still running rich. I put long tube headers on it, have it timed. 3L V6 engine, and it very suddenly developed this loping, stuttering idle problem. C. I R if that makes any difference. Come join the discussion about Silverados, Sierras, and other full size trucks performance, modifications, suspension, lift Reconnected the line. Engine appears to have been rebuilt (pistons are stamped . Joined Aug 14, 2001 Posts 8,146 Reaction score 2,656 Location Oak Harbor, WA. 350 TBI runs rich. See my previous post: 350 TBI Running extremely rough, can't solve. Post: SOLVED: 94 K1500 350 TBI rough running when warm (Topic#347478) tweezak Forum Newbie Posts: 8 Loc: OR Reg: 02-03-14. Exhaust smells like fuel. The exhaust smells "gassy" like it is running rich. Post: 1990 350 tbi Vacuum Leak, Running Rich?!? (Topic#327925) johnboy1022 Newbie Posts: 47 Reg: 08-14-15. I can drive it up and down it will only go about 40mph then when I get home it shuts off. 95 Chevy S-10 4. I replaced the fuel filter and measure 12 psi fuel pressure steady at the filter. 7 running rich? (Topic#283589) bluelang Forum Newbie Posts: 14 Reg: 07-03-12. Hi all. My engine is running rich. I'm at the end of my rope with this truck. The issue is that it runs very rich until I hit 30 miles per hour. It will go bad causing the ECM to think it's negative whatever degrees out and make the engine run rich to warm up. I stumbled across this post: Truck starts up fine, at idle it will backfire out left exhaust pipe and runs rich, poor mileage. New fuel filter too - Ecogard from Amazon. Most the time when I fire it up now it idles at about 400-550 rpms instantly no matter how cold or hot it is. User Info. Next Last. Now let me explain what i have done and replaced thus far. I replaced the whole distributor, the plug wires, and coil. Chevy Forums FREE technical assistance for your restoration and repair. Latest: Scooterwrench; 17 minutes ago; Chevy Forums FREE technical assistance for your restoration and repair. It started when I fired it up one morning and it didn't wanna high idle. 73-87 Chevy _ GMC Trucks » Author Topic: New member here looking for some help with 350 TBI running rich (Read 6535 times) gfritz25. It doesn't matter which white wire you use for the power or ground. on TBI units. 030 and I also got around 180 psi of compression across all . Finally broke down and took it to the local Chevy dealer who had the truck for three days. Premium. Did tune up, plugs, wires, cap, rotor, ignition module, o2 Tbi problems I have a 1990 chevy 1500 running rich. 1988 Chevy 5. Motor goes full rich on start up, which adds to the strain on the fuel pump. The spark plugs were just replaced. GMOTM Winner. 7L, Edelbrock MPFI, NV4500, Atlas, D44's, high steer, ARB's, 7" custom semi long-arm My 89 350 tbi 4 speed z71 seems to be running really rich all of the sudden. Run one white wire to a switched 12 volt supply (12 volts to the terminal only when the key is on), and run the other white wire to a good ground. Took it to two shops with no luck. 88XJ, Chevy 5. Chevy Silverado EV Forum 3K members. 3. I did notice that my scan tool will tell me my vehicle does not support a feature when trying to run live data or even look at the vin. m. Checked compression and all cyl were 125-135. Machine shop did the heads in full and cleaned up the block. This of course depends on the temp. 3 running rich, no power, low mpg. The fuel pump is not coming on when I first turn the key on. Doesn't seem to matter what gear I'm in or anything like that, but at 30mph you can feel the power drop back for a moment and then the power comes back and you can hear that it is much MUCH quieter and less rich. Model specific subject matter experts, classified ads and more. It runs great and idles well. AT4X versions of the GMC Sierra and Canyon. Ignition wires and cap recent new thermal sensor New O2 sensor New InjectorsWas running at almost 4% CO at read more Tbi running rich, non stock cam Engine & Drivetrain Tbi running rich, non stock cam - The 1947 - Present Chevrolet & GMC Truck Message Board Network Register or Log In To remove these advertisements. I always thought it was just too cold and not getting out of the warm up mode. This is a CRITICAL sensor to the efficient way a TBI system runs. If you have the issue again where it won't start and spits fuel out of the collector - unhook the wire terminals on the top of both injectors and crank the motor until it starts for a second and stalls. That's why the ECU can't trust the sensors to give it good info until it's up to operating temperature. Ok here is the deal. If it is running rich, you may have an injector(s) issue or possible the MAF (mass air flow) sensor is failing. Hold the throttle down for 30 seconds then it gets past that issue and is good to go. 1 cylinder. Thanks for the help! 4. My engine was missing an edelbrock 1406 carb and an HEI. it turns over for a few seconds, then has a fluctuating idle until warm, once put in gear the idle speed Hi, I have bought a 1988 Blazer that had a 454 engine swapped instead of the original 350 and it has a TBI, My problem is that the car runs way too rich and by reading some related post and some YouTube videos i have tested the common causes for a rich idle which are: MAP Sensor 5 to 0. My engine takes longer to start than I think it should. It sounds good, but my mechanic told me that its running rich and i should bring it in so they can see why. Monday at 12:39 AM. Running too rich. Ultimately i would diagnose it as running lean? Certainly not rich, i dont smell gas fumes at all. the problem is when in park or N the engine runs good with Customer: 1991 Chevy Step Van 454 TBI Emissions running rich at idle. Chevy Truck Tech I just got a new exhaust installed today. Was running great, until one day a couple of months in this thread in this sub-forum in the entire site. 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 Ok I am really frustrated with this one. russ130 Discussion starter. Not all 93 4. Had motor professionally rebuilt and have been chasing electrical gremlins ever since. Checked both spark and injector spray and nothing from both. 7 TBI running poorly open loop. think i can link it to bad gas, it only had a little in it when i got it and i added about a gal. 07-03-12 10:21 PM - Post# 2244287 Hey guys, 87 350 TBI when step on throttle runs rough and blows black smoke. It does not seem to do this when in park. New comments cannot be posted and votes cannot be cast. My 95 350 TBI was getting about 30% more fuel than it should at idle (data logs showed this). I have the same problem, and that is where I started (getting it to run closed loop). You can smell gas, under load you get backfires in the catalytic converter, on long trips the cat runs so Aside from that it runs and idles fine EXCEPT that most of the time it will exhibit a slight tip-in stumble. 350 TBI with turbo 350 trans. Ignition wires and cap recent new thermal sensor New O2 sensor New InjectorsWas running at almost 4% CO at idle. eax jbimq qxzys ijaaz cldahr qan kwyx icqy dnc ytajqy izbn ucrnxwi kewv wxsbt qsrrz