Re: 2003 Jeep 4.7l HO idle issues
Most of the time the problem is the TPS sensor, which sends the throttle position to the PCM. If you have a scanner whith realtime data, you could see the TPS in idle. On mine its around 12% and steady. When its much higher or fluctuating, probably the TPS is shot.
The idle air control stepper motor when not working right, normally doesn't give such high rpm.