Well heres my problem, I have a 2200 Turbo I had the motor buil in a shop. I have forged pistons,rods,camshaft pretty much the works. The problem is the motor will not run right it has a backfire out of the exhaust. The timing was checked and is right all sensors are good, but the computer was checked and it is reading 100% duty cycle when its off so when the car turns on it chokes and stalls. So of course my problem is the duty cycle but What could cause the computer to think its at full throttle when its off? If i rev the motor to 3 grand it will stay on and almost clear up but once i let off it dies down and stalls to much gas.