Just to provide some background, a guy in my town that owns a performance shop and does LS swaps asked me to come tune this car for him. I'm still fairly new to tuning and he knows that. The vehicle is a 54 chevy pickup that has a brand new GM LS3 376/525 crate motor in it. The guy bought his harness from PSI Conversion I dont really know much about the harness, but when I read the tune, the pcm is an e38 from a 2008 silverado. PSI also provided a separate tcm for a 4L60E. Anyways, the tune on the pcm from PSI Conversion was crazy. 5* timing at 6000rpm WOT, wouldn't idle at all, etc. To start, I actually found a GM tune for that specific crate motor and copied most all of the tables over onto my current tune. Now, it idles excellent, but as we revved it up at idle, the P0606 code appeared and it went into limp mode. We cleared the code and revved it some without any problems, but then it came back again. It only appeared with quick transition from idle to higher rpm revs. Also, the TPS seems to be off, as it was showing a lower position then what was actually being revved.
Has anyone experienced similar issues? Like I said, the tune that is currently on it is the tune from GM for that 525hp LS3 crate motor. It is pretty much a stock LS3 crate motor tune with idle raised and a few other minor differences. I will upload the old horrible tune and the new one so everyone can check it out. Please let me know what you think. Thanks.
LS3 525hp PSI conversion original tune.hpt
LS3 525hp PSI conversion (GM tune copied over).hpt
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Originally Posted by GHuggins
