I have a 2006 silverado truck was originally a 4.8 5 speed truck. i swapped the 5 speed out for a 4l80e. i changed the harness to an automatic harness as well as the ecu. the truck will crank but will not start. and the throttle body will move at first then i press the gas pedal the truck say reduced engine power and the throttle body quits moving. was wondering if i need to change any other harness on the truck or change some wiring on the truck to get it to crank?