02 F/B LS1 heads,cam,intake,injectors etc.. Built 4L60E. On the track, it launches the car shifts 1-2 at 6500, you shift to third and it acts like it is in nuetral and bangs off the limiter! You can pedal the gas and it will shift. The line pressure is okay (100psi @ idle, 230psi WOT). The shift points in the tune are set at 6500 and the limiter is set at 6800. If you stick the car in third and launch, then as it shifts itself into second you manually shift to forth, it will shift to third fine! I know the overrun in forth will apply more pressure and I am wondering if it may just be a tune issue?

 

i had the same issue. with my hptunes i just took the 2-3 shift speed down 3mph and now it doenst bounce anymore and shifts firm.