Leeroy_Z28

Basically asking because I just put a newer motor in my 2001 Z28 that threw a rod through the side of the block at 80k. So the car sat for around 2 months or so give or take a few days and the battery was disconnected the whole time a guy I know said that a tune would be wiped if it was sitting for that long. Haven't given it full throttle yet as it has all new seals on it and timing chain and sprockets but my car before when I would floor it would almost bounce off 5900 rpms. Hard to explain in wording. Sorry if there's already a posting on here about this topic I have only seen cases for about a week or so with their battery disconnected.

Thanks for your help and knowledge ahead of time.

King Nothing

iTrader: (9)

Haven't heard that happening. 7 years ago my car sat for 9 months before another engine was put in, I took the battery out the first day and the crappy tune was still there when I hooked back up. Just recently it sat disconnected for almost 4 months, just hooked it up the other day and the current tune is still on there.

RPM WS6

iTrader: (3)

My advice is to not listen to this individual regarding SEFI PCM calibration ever again. It's absolutely false, nothing about the actual "tune" will ever be lost unless the PCM is reflashed or fried. On the other hand, certain "learned" values will be reset, but those will relearn on their own just as they did previously (and this would happen whether the battery was disconnected for 30 seconds or 3 years.)

fst100

iTrader: (5)

^this

01ssreda4

iTrader: (96)

The learned trim data when reset can cause some erratic idling and driving for a few drive cycles. I've found that to be somewhat normal with these PCMs. Also, the 4l60Es have some adaptive learning inside the PCM that's reset as well. But no, the hard coded tune doesn't go away or change itself.

Docrocket1967

iTrader: (1)

This right here