1989 Firebird running rich
#1
1989 Firebird running rich
I have a 1989 Firebird with the 2.8 and a 5 speed. It is running super rich (like eyes watering rich) to the point it will barely run. I pulled the plugs, cleaning them and and regapped them. New cap and rotor and basically new spark plug wires. Originally I thought it was running bad due to a spark plug wire that has fallen on the exhaust manifold and burnt through in a small area, so I replaced that and went to drive it and it would barely accelerate up a hill. It also doesn't sound like it is running right, either. I hook it up and did some data logging with TunerPro and it seems I may have a couple things that aren't right.
First, it is running in Open Loop mode, BLMs in the 140s, Oxygen sensor is reading mostly "Lean", but since it's in open loop, it should be ignoring that.
I also suspect my O2 sensor is dead, probably due to the rich condition.
What could cause it to run so rich with so high of BLMs at idle?
Thanks,
Douglas
First, it is running in Open Loop mode, BLMs in the 140s, Oxygen sensor is reading mostly "Lean", but since it's in open loop, it should be ignoring that.
I also suspect my O2 sensor is dead, probably due to the rich condition.
What could cause it to run so rich with so high of BLMs at idle?
Thanks,
Douglas
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Car: 88 Firebird.
Engine: 383 HSR
Transmission: 700R4
Axle/Gears: 9 Bolt, 3.27:1 Diskbrakes
Re: 1989 Firebird running rich
Exhaust clogged anywhere? Like the cat?
MY cat broke internal and shifted sideways inside. I could do 30mph max with my foot to the floor and it was very rich out the tail pipe.
MY cat broke internal and shifted sideways inside. I could do 30mph max with my foot to the floor and it was very rich out the tail pipe.
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Car: 2003 Hyundai Tiburon GT
Engine: 2.7L V6
Transmission: 6-speed
Axle/Gears: 4.41
Re: 1989 Firebird running rich
Check the resistance of the CTS when cold and then check the film inside the MAF to make sure it's flat. The CTS may not be setting a code but be out of spec, and I've had MAF sensors fail without coding before. Both will throw fuel into the mix.
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Car: 89 RS 89 iroc 87 firebird
Engine: 3.1 Turbo/ 355 twin turbo
Transmission: a4 w/ 4500 stall/ a4 / t5
Axle/Gears: strange s60 /w 3:42's
Re: 1989 Firebird running rich
if it fouled the plugs dont clean them just replace them, acdelco standard plugs are by the the best r42 or r43tsk's. once u do that unplug the o2 and see how it runs, also check the fpr to make sure the diapghram didnt tear
#7
Re: 1989 Firebird running rich
No, I have not. That was my #1 thought until I checked the datalogging and found that the computer was commanding a rich condition.
Thanks,
Douglas
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Car: 89 Firebird
Engine: 2.8L out of a 89 camaro
Transmission: 5 speed
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Re: 1989 Firebird running rich
whens the last time u changed the air filter? plugged filter will make rich condition every time
#9
Re: 1989 Firebird running rich
Went out and played with the car more today. Unplugged the MAF, didn't help it run any better and oddly enough... the car realised the MAF was unplugged however in the ALDL values the g/sec would go up and down when I revved it. So I then plugged it back in and unplugged the O2 sensor. That seemed to make a difference, however not once did the car's BLM change from 143.
I just wish the car had better data logging... it just doesn't give enough info and some of it is weird (like the MAF g/sec values changing even when the MAF is unplugged). Also, I noticed that INT never changes. The O2 sensor value also was there but for some reasons the "switches" value kept going up and down, even with the 02 sensor unplugged. I am really about it just get my 91 Formly going and park the V6 and prep it for a hybrid swap. At least then I'll be replacing basically everything in the fuel/ignition system.
I just wish the car had better data logging... it just doesn't give enough info and some of it is weird (like the MAF g/sec values changing even when the MAF is unplugged). Also, I noticed that INT never changes. The O2 sensor value also was there but for some reasons the "switches" value kept going up and down, even with the 02 sensor unplugged. I am really about it just get my 91 Formly going and park the V6 and prep it for a hybrid swap. At least then I'll be replacing basically everything in the fuel/ignition system.
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Car: 2003 Hyundai Tiburon GT
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Re: 1989 Firebird running rich
IIRC, according to the FSM, the MAF should be between 32-150 gm/sec, between idle and WOT. If the MAF is reading high, it will run rich. I know that when I replaced my last one, it was reading some 30% higher than it should have, but without tossing out code 33 (until the last minute before it got chucked).
Did you check the CTS temp when you were datalogging?
Also check the TPS% and that it's adjusted properly (if adjustable), check between the O2S pigtail and ground for possible grounding of the O2S wiring (need to disconnect the ECM for this). And also check that the tan O2S ground wire on the passenger's side cylinder head is grounded (it's with the black/white ground wire on the lifting eye stud) and clean.
Did you check the CTS temp when you were datalogging?
Also check the TPS% and that it's adjusted properly (if adjustable), check between the O2S pigtail and ground for possible grounding of the O2S wiring (need to disconnect the ECM for this). And also check that the tan O2S ground wire on the passenger's side cylinder head is grounded (it's with the black/white ground wire on the lifting eye stud) and clean.
Last edited by Maverick H1L; 07-17-2011 at 08:51 PM.
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