reving idle, throttle while driving
 

The idle revs up starting at 1500 and quickly going to 2000rpm over and over etc while stopped. It continues to push the throttle (bet 1500 and 2000rpm) while driving (and stopping). I have an automatic, and I assume the problem is electrical etc. What should I check first?
1995 Galant

RE: reving idle, throttle while driving
 

First the Airflow sensor. Located right after the air filter unit. Next i would check the idle air controller. That's kinda hard but there's a write up on it in the Vfaqs. (www.vfaqs.com) If thoses all turn out to be ok, then things might be a little more serious. Things such as engine timing and fuel delivery might be the problem. Hopefully though, those are two very common parts that can go bad over time, so the probem might not be to costly.