I am helping a friend with a 06 truck 4.8 LS swapped into a 48 Chevy truck. He installed the complete engine, trans, UHJB and wiring harness. I have been tuning the VE table with the MAF failed and I am getting fairly close at the low throttle and low RPM areas. Then I had him get into the throttle a little harder and noticed it did not pull very well. I had him do a 2 second WOT run and noticed that the TPS would not go any higher than 38% even though the APP was 100%. I also noticed the timing was at 35 degrees when this happened so the PCM was not pulling timing out. We can turn the engine off with the key on and it will work properly up to 100% but when the engine is running I have never seen the TPS over 38%. Also the engine is running fine with no misfires. Any body have any ideas? I forgot to save a log file the last time we ran the truck. He is coming over tomorrow night for another tuning session and I will get a log file and the CAL so I can post them if nobody has any initial ideas. Thanks for any assistance you can provide.

Dwight
Nashville IL