T42 reverts back to stock part throttle shift settings

[Pekka_Perkeles]

This is strange.

For some reason T42 reverts back to stock part throttle shift settings, even if the file has been modified. Both "write calibration only" and "full rewrite" has been tried.

What makes is more strange is that it doesn't do it every time.

Here's stock and modified tune file, as well as a log where it goes very quick to fourth gear at slow speed.

01 stock.hpt

22 final.hpt

21 goes to fourth gear very early.hpl

[blindsquirrel]

I'd suspect the after-wrtie procedure - close editor write dialog, close editor, key off, open+close door, wait ~30 seconds before key on.

[Pekka_Perkeles]

Ok, thanks. This is a -57 Chevy with engine/trans swap, but I'll try this somehow anyway.

[Pekka_Perkeles]

Another one with same problem:

https://forum.hptuners.com/showthrea...Swapped-issues

[Pekka_Perkeles]

Well, it seems that the problem may be related to the 4WD with the donor car.

Do I have to do SPS programming for T42 with 2WD VIN to get this thing shift correctly?

[mikez71]

I notice when I load a 2WD vs 4WD tune, the shift schedule layout looks different. So what you're saying sound right to me..