Losing TPS at end of pass

[miamifan21]

I am losing TPS at the end of every pass at the dragstrip. Accelerator pedal stays above 100 whole time. Does anyone know what would cause this.

2004 GMC sierra 1500
6.0 lq4 SBE with TSP LS1 Bald Eagle cam, stock intake, stock 78mm throttle body DBW
60 lb/hr Deatschwerks injectors and 400 Deatschwerks fuel pump. fuel pressure is set at 58 psi.
76mm Turbo
4l80e with protorque 3200 stall

Also did it with 5.3 SBE that was in the truck before.