Maybe closed '4L80E, tuning help' a bit early?

[DeltaT]

I can see why you close some of the threads, but that one wasn't resolved yet.

I was going to add:

4L80E is stock gearing, the tranny shop put in a "stage 2 shift kit"
TCI computer and harness

All he wants is a factory tune that will behave predictably. Here are 2 symptoms of the tune:

- when he gets on the throttle, the trans will not shift unless he lifts the throttle.

This can also be a symptom of an incorrectly installed shift kit, like a ball in the wrong hole or a hole left open that is supposed to be plugged. The exact same thing happened to me when I had a supposedly 'great' tranny guy work on my 4L60 and screwed the Transgo shift kit install up, you know, the one with the supposedly 'idiot proof' instructions.

Anyways, it's worth checking, because it does not sound like a common programming error.

Jim

[KEISLER]

also, go in the software and confirm the TPS voltage readings and the % range. If the TPS is not calibrated correctly, the transmission will not perform correctly at all, up to a complete failure of the transmission due to lack of adequate line pressure commanded by the TCU.