427 lean condition/O2 sensor help
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Joined: Jun 2007
Posts: 130
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From: Tallahassee FL
427 lean condition/O2 sensor help
2006 A6, e38 PCM. Finally got my engine, and over the past few days got it in the car. It's an L92/6.2L stroked to 427. Running L92 heads that have been worked, along with a ported L76 intake, LS7 injectors (40lb/hr), etc etc and so on. It runs, it idles. When in OPEN loop, it will idle around the 14-15:1 range. When it hits closed loop, it almost immediately starts pulling fuel and goes way lean. This doesn't get better as the revs go up. It ends up pulling over 20% fuel according to the fuel trims. I noticed that the O2 sensor readings start going wild around this time too. From 900 mv down to the 50's, then back, then back, etc. Both fronts do this "switching". The only way I've found to stop this is by going into open loop.
Ideas? Suggestions? The tuner-type folks can pipe in too (files are here http://www.hptuners.com/forum/showthread.php?t=16094)
Ideas? Suggestions? The tuner-type folks can pipe in too (files are here http://www.hptuners.com/forum/showthread.php?t=16094)
