Can I has fuel? Car is lean... (scan inside)
10-09-2008, 02:18 PM
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Can I has fuel? Car is lean... (scan inside) Sort of beating my head against the wall a bit on this one, so I'm looking to you guys for some help. Car is a 2000 M6 F-body.
Its a stock LS1 motor with a P1-SC, and an ATI "can tune" through a diablosport. If you look at the scan you'll see that at idle, the fueling is okay for the majority of the time. Any time you push on the throttle slightly, it goes way lean. It also goes very lean if you blip the throttle while its in neutral.
You can occasionally feel the car stumble (it isn't missing on any specific cylinder) at idle and occasionally while under light throttle.
What we've tried...
Checked fuel pressure.
Disconnected the ATI supplemental fuel pump and checked pressure.
Open loop.
MAF only, no VE reference (CL MAF only in the scan file attached).
Checked for vacuum leaks, couldn't find any.
Checked for a bad plug(s).
Any suggestions here? Hoping somebody has run into something similar. This is a bit of a headache. I also believe this issue is independent of the blower.
Its a stock LS1 motor with a P1-SC, and an ATI "can tune" through a diablosport. If you look at the scan you'll see that at idle, the fueling is okay for the majority of the time. Any time you push on the throttle slightly, it goes way lean. It also goes very lean if you blip the throttle while its in neutral.
You can occasionally feel the car stumble (it isn't missing on any specific cylinder) at idle and occasionally while under light throttle.
What we've tried...
Checked fuel pressure.
Disconnected the ATI supplemental fuel pump and checked pressure.
Open loop.
MAF only, no VE reference (CL MAF only in the scan file attached).
Checked for vacuum leaks, couldn't find any.
Checked for a bad plug(s).
Any suggestions here? Hoping somebody has run into something similar. This is a bit of a headache. I also believe this issue is independent of the blower.
10-11-2008, 09:51 AM
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Info to add...
Lots of random misfires, but none trip the P0300. Swapped out the crank position sensor with no change.
Unplugged MAF for idle/part throttle tests, and the problem still exists.
The car is driveable with the issue its having, but the bottom line is it still has a serious issue.
What would clogged cats likely do to the scan? The clogged cats I've seen will always glow bright orange after driving for a few minutes, but these show no signs of overheating.
Lots of random misfires, but none trip the P0300. Swapped out the crank position sensor with no change.
Unplugged MAF for idle/part throttle tests, and the problem still exists.
The car is driveable with the issue its having, but the bottom line is it still has a serious issue.
What would clogged cats likely do to the scan? The clogged cats I've seen will always glow bright orange after driving for a few minutes, but these show no signs of overheating.