I pulled the Idle Speed Controller and while car was running moved the plug around and nothing happened, nor did the little bulb come on that I have connected to the two Idle Air Valve. I then, while the car was running, took another of the spare Idle Speed Controller units I have, plugged it in and tried the same thing, and got nothing from that one. But, I then got the 3rd spare Idle Speed Controller unit and plugged it in while the car was running and the bulb came on and the engine died.

I tried the same procedure all over again and got the same results. Now, when I used the first two Idle Speed Controller units the car will start (easily), without having to put my foot on the pedal, and idles at 1200rpms.

But when I try to start the car with the 3rd Idle Speed Controller unit (the one that bulb comes on, but kills the car when idling) it will not start without pressing the pedal down a little, and will die if I take my foot off the gas. I have to hold the pedal down to keep it around 800-1000rpms to keep it running. It's like the Idle Air Valve is choking/cutting off the air which makes the engine die.