2004 gmc sierra 1500
6.0 lq4 Tsp bald eagle boost cam, stock truck intake, stock dbw throttle body
hughes performance 4l80e with protorque lsxt converter
76/75 precision turbo on 15 lbs of boost
3.90 rear gears on 28" slicks
I recently pulled my motor and sent my converter off to change the stall from 2800 to 3500. I installed the converter and motor and went to the track to test. Now it wont shift wot into 2nd gear. It just hits rev limiter. I notice on my first log, the tps only got up to 80% and each pass it would be lower and lower. My last pass, it only read 20%. On my first two passes, I did my burnout it acted like it wouldn't shift either and as I would creep up to the line to stage, it acted like it would shift and very little throttle and die.
The truck worked fine before stall change. The logs are my first and last pass.
I'd start with checking the transmission fluid. Make sure it's full...even 1/2 qt overfull will work better for what you're doing with it. Check the smell too. Does it smell burnt? You might even drop the pan to look for debris. Make sure that the filter is in good shape and not clogged.