Thanks for your reply. I think it is the Idle Valve that I need to test. Its the one with the plastic adjustable screw beneath it that adjust the flow of air! I had some rough idling problems with my car.. I played around with the little screw and my problem is gone now. But it would come back once in a while (interminently). I cut electricity going to it)!!! And it did not make any difference as far as idling and engine performance. So I am guessing that the idle valve is not functioning properly, or not functioning at all! So your help will be appreciated!