I've got a 1994 Honda Civic EX. When I start the car the idle will jump 500 RPM (from maybe 700 RPM to 1200 RPM), then drop, then jump back up, rhythmically up and down. It continues to do this even when car has warmed up...Any ideas why it is doing this? Could it be the Idle Air Control?..If this is the case, could it possibly be just carboned up or something, and if so, how do I go about cleaning it? Any ideas?