Running Lean Up Top Bad!
Running Lean Up Top Bad! Car is running 14.6 A/F after 4400 rpms. We dumped as much fuel as we can with edit. But cannot get the A/F richer. Down low its rich, but up top lean. We thought it was the injectors(stock 99s). So we swapped to 30lb SVO. Still the same problem. Under 4400 rpm got it to 12.5 A/F but over 4400 cant get it under 14.6. This is with the cutouts closed running through SLP Dual/Dual. Anyone have any insite on this. Here is the break down of the car.
99 Camaro SS
Stage 2 Heads 2.02/1.57
226/230 .574/.575 112 Lunati Cam
1 3/4 QTP Merge Collector Heads
3" QTP Y Pipe
SLP Dual/Dual
4.11 12 Bolt
LS6 Intake
LS1 Edit Tuned
Any input is most appreciated
99 Camaro SS
Stage 2 Heads 2.02/1.57
226/230 .574/.575 112 Lunati Cam
1 3/4 QTP Merge Collector Heads
3" QTP Y Pipe
SLP Dual/Dual
4.11 12 Bolt
LS6 Intake
LS1 Edit Tuned
Any input is most appreciated
Re: Running Lean Up Top Bad! Yes, wideband. tomorrow going to over a few things again.
Check fuel pressure at wot
Check the o2 sensors
Might think its the fuel pump, but dont know.
Check fuel pressure at wot
Check the o2 sensors
Might think its the fuel pump, but dont know.
TECH Addict
Joined: Nov 2001
Posts: 2,207
Likes: 0
From: College Station, Tx
Re: Running Lean Up Top Bad! Fuel pressure isn't dropping at WOT when you go lean? If not the fuel pump is fine. What are injector DC looking like? What does the MAF do when you are going up - does it flatline or does it continue to increase?
TECH Resident
Joined: Nov 2002
Posts: 996
Likes: 0
Re: Running Lean Up Top Bad! Fuel filter maybe?
Also log the injector pulsewidth. Maybe that will give a clue. Ex. if the pulse is very long and it is still not getting fuel, then there is some pressure problem. If pulse is short, then the computer is not keeping the injectors open long enough...
Good luck.
Tommy
Also log the injector pulsewidth. Maybe that will give a clue. Ex. if the pulse is very long and it is still not getting fuel, then there is some pressure problem. If pulse is short, then the computer is not keeping the injectors open long enough...
Good luck.
Tommy
Re: Running Lean Up Top Bad! A couple things to try....
1) Reset the PCM. Unplug it and let it sit. We had this happen once and resetting the PCM did the trick.
2) Keep the car in open loop (just for a trial run)
3) Start over. Load your original stock program and start over if the problem persists. It sounds like a program problem.
1) Reset the PCM. Unplug it and let it sit. We had this happen once and resetting the PCM did the trick.
2) Keep the car in open loop (just for a trial run)
3) Start over. Load your original stock program and start over if the problem persists. It sounds like a program problem.
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Re: Running Lean Up Top Bad! I've seen this happen on a car with an aftermarket pump and gas at 1/8 tank.It was somehow uncovering the pump.Also at 4400 it could kick in Cat overtemp which ussually makes A/F go real rich.(not lean)
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