Pontiac Repair: 93 pontiac grand am high idle, vacuum leak, throttle positioning sensor

Question
93 Pontiac Grand Am 3.3L V6 Two weeks ago it started idling very erratic. 300rpm to 1500rpm. I changed the throttle positioning sensor and the erratic idle quit.Now it revs to 2000rpm on start up and won't idle down until you put it in gear and drive it maybe 20-30 feet.Put it in park or neutral and it then idles around 1100rpm still to high any thoughts?

Answer
Hi Dan.

A few thoughts. either ther is a vacuum leak somewhere. The TPS you put on it incorrect for the car or is out of adjustment or you have an Idle control motor that is not working correctly. If you have a scan tool the TPS reading on that engine should be low at idle like .35V to .42V if it's any higher than that it will cause a high idle. Good luck :)