Pontiac Problems? Ask a Mechanic for Answers ASAP
Hello and welcome to just answer and allowing me to assist you sometimes another eye can spot thigs others can't so lets give it a try.is this a cable throttle or by wire?
Have you disconnected the cable from the throttle body to see if that stiffness is in the cable or throttle body?
Have you ever had the injectors power flushed because if they don't have a proper spray pattern to animize the fuel to burn properly it will do those symptoms. at this mileage i would illuminate that and put a good fuel system cleaner such as Lucas in the tank to follow up. Without ant codes I would start there. Also do you or can get a vacuum gauge to check manifold vacuum/?
check you EFI and engine fuses
depends which one is gone. but still wouldn't hurt to do that injector flush at that mileage.
The other thing is and I know this is why people come on here looking for a quick fix but because of the complexity of engine managements on these cars today, I strongly recomend to do a full scan and active test , this shows a good tech how all the perimeters are operating and gives one a better idea where to start.
LOL lets not shoot the goose yet until we have all those findings.
Your thinking too hard lets do this in logical steps as I mentioned or you'll go bananas. illuminate one at at time that may cause this.
remember one step at a time.
Morning, ok going over our notes.Have you disconnected the throttle cable to see if that stiffness was in the cable or other wise? have you power flushed the injectors? This is what I would recomend now, power flush the injecters ,replace the throttle body with tps sensor.
very well. the difference with doing a proper injector flush and just putting cleaners in the fuel tank is the stuff you put into the tank is very deluted and works over time ,but power flushing goes right to the injecters with a strong cleaner to properly clean the nozzles for maximum spray pattern .