Hi I have a friend who has a 93 civic and her car is acting weird. When the engine is cold the RPM's are at 1500 and when the engine warms up it raises at 2100~2200 RPM's.
Then she drives and puts it in gear the cars RPM's drop too about 1000~1200 but when she puts it in neutral it goes back up to 2100~2200. What can be the problem?

By the way the car is automatic.