Thanks anyways man 
Fuel Trims Problem HELP!!
Fuel Trims Problem HELP!! after the new motor went in, we had some problems getting it to idle (408 A4+Big Stall)
Once we got it to idle, it was running WAY to rich. We scanned it, and saw that on bank 1, the the fuel trims where at 25%. We reset the fuel trims, then it idled PERFECT.... even while in gear!!
after a few minutes though, bank one fuel trims went back to dumping 25%... the O2's are switching fine, the numbers are kinda high though (700-900)
My guess would be the 02's, what do you guys think?
any help would be great!
Once we got it to idle, it was running WAY to rich. We scanned it, and saw that on bank 1, the the fuel trims where at 25%. We reset the fuel trims, then it idled PERFECT.... even while in gear!!
after a few minutes though, bank one fuel trims went back to dumping 25%... the O2's are switching fine, the numbers are kinda high though (700-900)
My guess would be the 02's, what do you guys think?
any help would be great!
I would guess one cylinder is skipping. The unburned air causes the o2's to read lean, causing the pcm to dump fuel, causing the other cylinders to run rich. I'm guessing big stall means big,lopey cam, so you might not notice a cylinder skipping at idle. This is of course just a guess.
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Joined: Jul 2006
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From: San Diego
Originally Posted by chrismcdaniel
after the new motor went in, we had some problems getting it to idle (408 A4+Big Stall)
Once we got it to idle, it was running WAY to rich. We scanned it, and saw that on bank 1, the the fuel trims where at 25%. We reset the fuel trims, then it idled PERFECT.... even while in gear!!
after a few minutes though, bank one fuel trims went back to dumping 25%... the O2's are switching fine, the numbers are kinda high though (700-900)
My guess would be the 02's, what do you guys think?
any help would be great!
Once we got it to idle, it was running WAY to rich. We scanned it, and saw that on bank 1, the the fuel trims where at 25%. We reset the fuel trims, then it idled PERFECT.... even while in gear!!
after a few minutes though, bank one fuel trims went back to dumping 25%... the O2's are switching fine, the numbers are kinda high though (700-900)
My guess would be the 02's, what do you guys think?
any help would be great!
Its a SD tune, no MAF.
im possitive the plug wires where all connected, and the plugs are all new. i wasnt getting any midfires on the scan.. The came is HUGE though, so it does run rough at idle.
also, its only happening on one bank.
im possitive the plug wires where all connected, and the plugs are all new. i wasnt getting any midfires on the scan.. The came is HUGE though, so it does run rough at idle.
also, its only happening on one bank.
Last edited by chrismcdaniel; Nov 23, 2006 at 01:29 AM.
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Originally Posted by Black02SS
If you are seeing them peg at 25 on only one bank, I would check for a vacuum leak somewhere. It could be around the intake or one of the vacuum lines on the back came undone.
thanks,
chris
Basically the motor is two halves. If you have a leak on one side, then you will only notice it because the O2 for that side notices a lean condition due to the extra amount of air and tries to compensate for it, hence the +25 trims. 
Originally Posted by Black02SS
Basically the motor is two halves. If you have a leak on one side, then you will only notice it because the O2 for that side notices a lean condition due to the extra amount of air and tries to compensate for it, hence the +25 trims.
Originally Posted by 98 Raptor TA
i had the same problem and it was a leak at my header collector. Check for exhaust leaks or intake (vacuum) leaks
I have been helping Chris with his car and I am stumped. Here is the update as of today.
The car will run with both banks locked at zero until it warms up and then bank one runs lean all the way to -15.6 and stays lean. Bank two stays locked at zero. We set up a misfire scan and read zero misfires even when we unplugged a wire from the coil packs. We also changed the O2 sensor with no change. There were no vac/ or exhaust leaks found.
Any ideas?? Injector or coil packs bad maybe??
The car will run with both banks locked at zero until it warms up and then bank one runs lean all the way to -15.6 and stays lean. Bank two stays locked at zero. We set up a misfire scan and read zero misfires even when we unplugged a wire from the coil packs. We also changed the O2 sensor with no change. There were no vac/ or exhaust leaks found.
Any ideas?? Injector or coil packs bad maybe??
Originally Posted by Black02SS
Switch the plugs/coil packs from one side to another if you think that is the problem. I still suspect there is a leak somewhere.
