HRD

iTrader: (1)

I have an LS7 on an engine dyno for some cam testing. At the end of a pull when the dyno operator lifts off WOT, we loose throttle control. The throttle goes to idle showing 29% TPS and stays there regardless of the pedal position. Generally if we cut the engine off and wait about 30 seconds, then restart it works fine. Sometimes if he eases out of the throttle real slow it doesn't mess up. Any suggestions?

Reving and otherwise, it works fine.

NoGo

iTrader: (2)

I know its on an engine dyno, but can you pull codes?

I would guess some sort of TPS discrepancy. Then when you restart it re-runs the TPS test and says everything is fine...... just a shot in the dark though.

ivmotor

iTrader: (2)

I ran into a very similar problem last year. It ended up being the wrong throttle body. There is a bronze throttle plate and an aluminum throttle plate and they have different properties for tps match. Make sure your throttle body matches your operating system.