You will have to go back to my first reply and understand what I said.

I believe that the system is in the "prepare to idle" condition (my terminology). Let me describe the concept. The car is being driven down the road. The rpms are greater than the idle valve control. If there wasn't a different mode the idle valve would be driven closed trying to control the idle. The controller knows that the engine is no longer idling by a number of functions: the idle throttle switch, the decel switch (on some models) and the position of the airflow meter flap.

During the "prepare to idle" situation the airflow is held at a position greater than the unloaded warm idle position. This is so that if the throttle closes quickly the engine doesn't die. There is no printed strategy that I know of here, but I believe that there are levels of idle air motor position based upon the various conditions (above) being satisfied. Thus if the idle switch is open and the airflow pot shows off idle conditions a larger position is created say large enough to run a motor 1000rpms. As the throttle switch closes the airflow drops to that which runs the motor say 700rpms and when the airflow meter pot goes below .7v the idle control system takes over and varies the airflow to maintain a constant rpm no matter the load.

It is my conclusion that you are in this last stage of "prepare for idle" condition and no control exists. In such a position changing the parts won't change the answer as everything is doing as commanded.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician