Tallnate

I've searched for hours and hours with no luck. Anyone have an idea?

PROBLEM:
2008 LY6 truck motor swap is complete but the engine won't rev past 4,000 rpm's. It's running good, just holds right at 4K with the pedal on the floor.

componets i'm running:
2008 LY6 running factory VVT cam
2009 vette E38 w/ manual. Factory truck tables were flashed on it by PSI
PSI stand along harness specific for this motor
Old school manual tranny so no VSS hook up
Original truck style intake and MAP
Original truck style MAF
Original truck DBW throttle body assembly
Corvette DBW pedal

We've tried several different PCM's and I have the same de-fuel result at 4K with each. I've tried swapping pins and running my truck style pedal and it doesnt work either.

Also, at times (randomly) the accelerator will become completely unresponsive. When this happens i have to turn the ignition off for 10-15sec and restart the motor in order to regain pedal response.

getting a P0108 MAP circuit high voltage code but MAP test good and wiring/crimps etc are all good. (have 5 volt signal from PCM as expected so not sure why it's tripping an 0108 high voltage code)

Please, any ideas?
What scenario's could cause the PCM to limit throttle to 4,000 max rpm?


Thanks for any help you can share

85MikeTPI

iTrader: (9)

http://www.hptuners.com/forum/showthread.php?t=34993
http://www.hptuners.com/forum/showthread.php?t=36796

There are also some simple rev limits for Park/Neutral which the E38 may think you're in if the P/N switch input isn't hooked up..

Tallnate

Thank you 85Mike. Great info

rindoze

iTrader: (1)

FYI since I had this issue and there was no answers anywhere. You have to change the torque management for all the gears, and the DFCO for all gears (and P/N). In other words there are like 5 things to change that are limiting at 4000 rpm. There also may be an ETC limit to disable in DFCO.