I have a problem with my LTFT's NEVER going positive, and I'm trying to figure out why. I've read here, other LS1 sites, google, and found nothing that helps.
LTFT's average 0 to -14
STFT's I have seen swing from +5 to -43
At WOT they all do go to 0
It seems to run ok but the mileage isn't the best and the dead O2's I have plugging the post cat o2 bungs are sooty black.
It's been running about 1200 miles and the only problem I had when I first got it running was a dip to 400rpm in idle when coming to a stop. I fixed that by changing some numbers in the idle cracker table.
I just don't think a near stock car should be that far off, can someone please offer some ideas on why these numbers are so far off?
Here are details on the car.
It's a 2001 Z28 that I bought as a roller. It has an A4 trans.
I bought a 2001 LS1 for it with 83,000 miles, it was already wired. I cleaned it and inspected everything. The VCM is out of a 2002 T/A.
It's 100% stock except for a Lid, Gutted cats, TB bumpstop mod, TR55 plugs, AIR delete, And the car had a Racetronics fuel pump and wiring harness when I got it so I left it in. It puts out around 60-62 psi at the rail.
When I got it running I did 3 seafoam treatments.
The VCM had a custom tune so I did an entire re-write using the hpt file taken from my '02 SS. The only tuning done is deleted codes, TM, WOT AFR, misc transmission.