When I start my car, it usually runs up to around 2000rpm and then slowly decends to about 1000rpm (never below that). However, as soon as I touch the gas, say from a stoplight, the engine speed jumps back up. The car will basically propel itself at 40 mph without me even touching the gas. I have to use the brake alot in city traffic. Any ideas?
The problem went away when I repaired a couple of vacuum leaks but has returned, and the repairs I made are still holding.

When I had the same problem with my 94 it was the intake manifold gaskets $325 later no more problem.

For how long? How does it react if your remove the oil filler cap, while the engine is idling?

If the problem is the same, the cure should be the same. I would begin by looking for another vacuum leak. The tip of an unlit propane torch, used as a probe, might be useful in your search. Intake gasket leaks are not the only possibilities but, they can be harder to find and they are more expensive to repair.

I'm guessing klyons is making a comment, not suggesting your solution should be the same as his.

Norm

I once worked on a 3.4 that had a bad O2 sensor, and would basically propel itself to about 40... It did throw a code though. Not saying that you have a bad o2 sensor, just a comment.

Is your check engine light on at all?