2013 Mustang GT with a Diablo 93 Tune. The car came in with a Boss intake, FRPP Throttle Body and the diablo calibration with lots of drivability issues. I have most of the issues worked out but one I need some help on. The car will start and idle great with no idle issues. It can be driven with no issues and no return to idle issues. Fuel trim +/- 5%. The car does have some slight surging during cruise, not enough to see the tach move but enough to feel. After about twenty minutes of driving the idle will slowly go from 800 to 2500 over about a 1 minute time frame. Then the idle will drop down to 800 go back up and then go into reduced power mode. Turn the car off, restart and its all good for another 20 minutes. What could it be? Any one have parameters for the FRPP throttle body.
Thank You