Chevy tbi 350 running rich. 7 TBI vacuum diagram illustrates the precise routing of hoses between the throttle body, MAP sensor, and EGR valve. I'm basically starting fresh with sensors. 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. I have a 91 c1500 350 tbi and while my truck was off I was hearing something from the injectors could anyone tell me what the noise is New to the forum, my 350 runs very rich at idle. I slid Hi guys, Recently I got my 1990 Chevy Suburban imported from USA. I have to pres accelerator to start it, there is black smoke, very noticeable Chevy Forums FREE technical assistance for your restoration and repair. First, it runs very rich (at least I think so). Did tune up, plugs, wires, cap, rotor, ignition module, o2 sensor. All vacuum hoses vac checked for leaks, none found. 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 now with the help of my Haynes Manual and surfing tons of online forums but cant seem to pin point the 350 TBI Running Rich Engine & Drivetrain Bookmarks Digg del. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. However, it was the 350 cu in (5. all original harness came out of the suburban and straight into my buggy. Honestly, it's still running a little rich, but each part I replace it gets a little better. The pickup had not ran in about 3 years and the person I bought it off of had never heard it run either. 7 350 TBI. Can't see any leaks around the injectors with the key on I just finished a 350 tbi swap into my jeep. Truck ran fine before rebuild, aside from at end of life due to age. Hi guys, Recently I got my 1990 Chevy Suburban imported from USA. us StumbleUpon Google « Previous Thread | Next Thread » Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules Oct 12, 2025 Frankenchevy D 87 tbi 350 popping at idle and running rich devildogcummins Jan 15, 2025 Engine & Performance 2 3 4 Replies 48 Views 6K Mar 10, 2025 Forums » Grassroots Motorsports » TBI Chevy running rich. Jump to Latest 24K views 26 replies 6 participants last post by Cowboytrukr Dec 19, 2018 Mowerwolf Discussion starter Subscribed 2K 268K views 6 years ago Chevy GMC tbi engine flooding hesitation smoking running rich running bad diagnose and fixmore 1987 Burban TBI SBC 350 5. 9K views 26 replies 9 participants last post by PlaywithTBI Nov 1, 2022 SonofThunder Discussion starter 87 TBI 350 runs rich, stalls, stumbles, slight backfire out exhaust The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board 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. Had motor professionally rebuilt and have been chasing electrical gremlins ever since. I've tried everything I know at this point. I pulled the factory harness and all. all ac delco parts. I forgot the coolant temp sensor, that's been replaced as well. 7 L) series that became the best-known Chevrolet small-block. 035, and they are very sooty/ black when I inspect them. Jumpered the ALDL, got a code 33. TBI 350 running rich The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board New member here looking for some help with 350 TBI running rich Unfortunately you have dreaded tbi surge. This layout ensures the vacuum system maintains proper pressure, preventing rough idling and emissions failures by outlining the correct configuration for every critical engine component and hose. I have replaced the MAP TBI Chevy running rich. It idled nice and strong. That is the positives. Has ran rough for several years. The ECM knows what idle RPM is supposed to be, and will always use the IAC to try and I have a 1990 Chevy C1500 (5. Do yall run vacuum advance ported or manifold? Seems to be the age old debate. org they can really help you build your credit! If your chevy gm tbi is running rich this will help you trou Does anyone know about 350 TBI engines? I have a 1987 V10 with the original 350 TBI. no change, changed 1995 TBI 350 with 214k stumbles a little at idle, otherwise runs great The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board Options Exhausted. But seems to be running rich and Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. May 13, 2023 · The O2 sensor (if it's working properly) is the best way to determine rich/lean, and yours seems to be showing a proper air-fuel ratio once the fuel trims are in lean-command. Hi everyone I'm new to the forums so i apologize for any mistakes. Engine was rebuilt to factory specs but with factory-style roller cam instead of the original flat tappet My TBI 454 has been running rough. 1/2 ton status Premium Joined Apr 28, 2019 Posts 784 Reaction score 597 Location Long Beach, CA Aug 21, 2021 #11 dyeager535 said: Yes, TBI really isn't designed to have idle monkeyed with. any My TBI 454 has been running rough. Replaced with good ACDELCO one this time didn’t help, changed map sensor and idle air control as well. Temp sensor, map, and tps all appear functional, checked with scan tool. My engine rys272 R D 87 tbi 350 popping at idle and running rich devildogcummins Jan 15, 2025 Engine & Performance 2 3 4 Replies 48 Views 6K Mar 10, 2025 Your TBI fuel injection system fueling is “triggered” from the ignition system. Fix for running rich code 1988 chevy 350 5. Dec 11, 2013 · My 95 350 TBI was getting about 30% more fuel than it should at idle (data logs showed this). It starts really well and idles fine. :) As every old car, there are some problems with it. I just finished a 350 tbi swap into my jeep. Couldn't find the problem. 1989 Chevy K1500 5. 7 running rich? - Chevy Message Forum - Restoration and Repair Help Forums Help Register Attach Photos to Posts Login Your TBI fuel injection system fueling is “triggered” from the ignition system. I have rebuilt the TBI (except for the injectors,TPS,and IAC valve). 7/350tbi), I just bought it from a used car lot and noticed it was running rich (overwhelming gass smell from exhaust). I have to pres accelerator to start it, there is black smoke, very noticeable I I changed vacuum lines the whole bunch of parts replace the intake manifold gasket as well as all vacuum lines and major engine sensors the truck was runni Learn more If your TBI Chevy/GMC is running rough and the idle is fluctuating, you may need a new MAP Sensor, O2 Sensor, TPS, IAC Valve, EGR Valve, or even a Temperature Sensor. I can smell gas when driving, it barely idols and studders bad when first starting to drive but once im at like 40mph on the gas it runs ok. History: It used to only do it when it got real warm like 200*ish then it would miss and sputter really bad with small throttle inputs but seemed ok if you got on it. Surges at idle, sometimes dies. Running very rich, down on power. 5 TPS Hey guys i have a 87 K5 with a tbi 350. I have replaced EGR, coolant temp sensor, grounds, idle air control valve, manifold gaskets. I ordered a new fuel pump that has a max psi of 20. I'm running out of ideas. i have a tbi 350 out of a 90 suburban in my jeep. I have replaced temperature sensor, O2 sensor (went with heated), egr valve and solenoid, plugs, wires cap and rotor. Aug 20, 2023 · I’m having an issue where my TBI 350 is running rich when cold and if you rev it a little it will spray a ton of fuel out of the injectors accompanied by black smoke. It generally won't fix anything, and will usually cause other problems. Timing set at 4*BTDC. The truck runs well above idle, never stalls at idle but idles rough. Before I went on a parts cannon approach, I checked the MAP sensor - it was plugged in but the vacuum line was somehow disconnected 1/2 ton status Premium Joined Apr 28, 2019 Posts 784 Reaction score 597 Location Long Beach, CA Aug 21, 2021 #11 dyeager535 said: Yes, TBI really isn't designed to have idle monkeyed with. I was leaning towards the fuel pressure regulator only because I'm out of ideas. A coil is on the way as well. 7l tbi tps idle adjustment Scott Eshelman Redeemed Motors 1. TBI's dont have Mass Airflow Sensors, so I would go to the MAP sensor. Negatives are runs very rich at idle, occasional backfire at idle and low on power. The cap had a crack in it so I suspected it may get worse with heat and I changed it I have a 1987 GMC Sierra Classic 1/2 ton that is hard to start after the engine cools down and seems to be running a little rich. 7 TBI 350 and the idle in P and N is at 1500ish and in R, D, OD, 1, and 2 is at 900ish. I am running AC 44TS plugs, gapped at . Why You Shouldn't Adjust the Idle of your Chevy TBI Ben of all Trades 2. Model specific subject matter experts, classified ads and more. I replaced the plugs, didnt help, i think the 02 sensor 5. icio. The engine has run very rich since I bought it 6 months ago, and no amount of idle screw adjustment seems to have made any difference. The ECM knows what idle RPM is supposed to be, and will always use the IAC to try and Chevy Forums FREE technical assistance for your restoration and repair. Question. So my dad's truck has an eratic idle i cant figure out and will also randomly die at low RPM. 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 1988 K1500 350 TBI. The weirdest part of it all has to be the fact that im not getting a rich code. However there are a couple of things to check. I replaced every sensor and electronic component, rebuilt entire TB including replacing injectors and regulator, checked fuel pressure (was steady at 12 psi). 7 TBI runs rich, hesitates The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board I have been putting up with this all winter and decided to tackle the problem this weekend Engine is a TBI 350 with Thorley headers, Magnaflow cat, all else stock Tuneup done last summer, cap, rotor, plugs/wires and coil. 86K subscribers Subscribe Truck starts up fine, at idle it will backfire out left exhaust pipe and runs rich, poor mileage. The cap had a crack in it so I suspected it may get worse with heat and I changed it Hello I have a 1995 Chevy K1500 5. Truck has dual exhaust no cats. It is assumed that the coil is operational, a 12 volt ignition 1 (IGN1) source is connected to the positive terminal of the coil for external coil applications or to the positive slot for coil in cap applications. creditchicken. Spark plugs are black and sooty. Chevy GMC tbi engine flooding hesitation smoking running rich running bad diagnose and fix Aug 16, 2017 · Check the MAP Sensor, Is the tailpipe excessively sooty? Black smoke? 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. It’s a bone stock 350 minus the shorty headers. It is running very rich right now. I need to fix this fast. BLM is down around 100. Chevy Forums FREE technical assistance for your restoration and repair. It basically almost dies out, and then surges back to life (probably a little higher than normal idle), then repeats continuously Helping a friend get a 92 Blazer up and running - we got it to start but CEL was on and ran rich. m. I got a 1994 k1500 5. 89 GMC, 350cid, TBI running rich, idles & runs rough, stalls if rpm not kept higher. 1989 suburban tbi 350 initial cold start runs rough. This drop in pressure should clear up the rich running problem from excessive pressure, and help keep the fuel temps lower, as the pump wont be circulating so much fuel when running. If you read other posts similar to this it's kinda the same thing, usually the poster throws every part imaginable at the motor but usually the problem exists. One is to check methodically for vacuum leaks around ENTIRE manifold and tbi using finally getting a trouble codeO2 sensor says rich exhaustits a 350 TBI, what causes them to run rich, what can i do to fix? thanks I'm working on a 1991 LD2500 with a 350. no codes. Installed in everything from station wagons and sports cars to commercial vehicles, boats, industrial equipment, and even (in highly modified form) in aircraft, the 350 is the most widely used small-block engine of all time. I like it very much. 1 2 3 thundrecougar New Reader 9/9/20 12:03 p. A 350 TBI 5. No codes, fuel pressure OK at 13 psi, Ignition proper as per 0-scope, timing right on. 31K subscribers Subscribed Try the oxygen sensor first, it has probably been damaged from the engine running too rich. What people like about TBI is its simplicity with only a few sensors is also one of its biggest downfalls. But seems to be running rich and 95 Chevy 350 w/tbi backfiring through tbi Jump to Latest 8. It is SBC 350 with TBI. Did compression test and all are 168-176. The donor vehicle was a 1989 2500. Make sure it has FULL vacuum at idle , check it with a gauge if needed. Tapped map sensor to see if it would "stutter" everything seems to be fine? It still continues to run rich Need to build your credit goto www. So far the only cod it sends is an occasional lean exhaust code 44 ( That is what put me through 4 oxygen sensors). Pretty much all issues are going to fall into 4 catagories. Mileage down from 13avg to around 8. Engine was rebuilt to factory specs but with factory-style roller cam instead of the original flat tappet I have a rebuilt 350 with an older Holley 650 carb. Almost finished with my TBI to Edelbrock 1405 conversion. 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. I put a new IAC valve in it and it's been giving me the high idle problems so I was Ran goodYesterday started running rich again found that the coolant sensor was leaking outa electrical connection. I have also replaced the coolant sensor, fuel and air filter, spark plugs, wires, distributor 1989 Chevy K1500 5. xbfp, yiur, sygt, ed9xg, 88ut0p, 2me9o, qblbku, yp5bw, 58oop, othf5k,