2003 Chevy Cavalier occasionally dies at stop signs, throttle sticks, engine throttles up?
I'm trying to troubleshoot my mom's car and I'm getting a bit stuck. She has a 2003 Chevy Cavalier and it'll run fine most of time but keeps having major occasional problems. These problems only happen in winter (when it gets below freezing).
1. Sometimes dies at stop signs. Have to leave car off for about 1 minute and then try starting, otherwise it dies again right away.
2. Throttle occasionally sticks. If I pull over and wait 20ish seconds the throttle will unstick, but won't unstick if I keep driving.
3. Engine throttles up by itself up to 2000RPM. This can happen when driving or when stopped.
Since this happens during winter, number 2 and 3 are dangerous and I'm confused with what it could be. I was thinking Idle Air Control but it just doesn't seem to fully fit the picture. One other thing that wrong with the car is that the cooling fan isn't working, I haven't put the new one in yet but I don't see why that would make the car not work in winter, it was still working ok in summer/fall.
Ideas?
No codes are snowing, I hooked it up to my OBD but nothing looks glaringly wrong with the live data.
The car is maintained fairly well and usually runs perfect, its just when it has it's hicups here, they could get someone killed.
Just an FYI if anyone finds this in a search:
The issue was resolved by replacing the intake air temperature sensor (11 dollars and 1 minute job), and replacing an end on a fuel/vacuum cable that connects to the air intake. The split cable was dumping gas into the intake and spraying it around the engine compartment. I also replaced the gas cap since the seal was shot.