I shouldn't be suprised, the idle air control on my 82 245 turbo had been acting weird for months now. Today it decides to get stuck and my car is idling at 3000 rpm. I take the hoses off and douse it in carb cleaner. No change. So I go over to this old B18 sitting in the corner of the garage and cut a piece of heater hose off it, then scrounge around in my box of plumbing parts till I find a valve. Slap it in between the air lines (with the IAC still connected) and dial it in for 800 RPM. Car runs great.

Now.. Can someone explain the theory of operation of this thing to me? Tomorrow, when the engine is cold, I suspect I'll have to go out and fiddle with the valve till it warms up. Is the valve closed or open on a cold engine? Lastly. I'm curious how this valve is designed to work. I understand it has a internal heater and is also affected by engine heat. Is it only closed/open only depending on the heat is senses, thus acting solely as a choke?

Here's my handiwork.