Idle air valve check / adjustment

wayne,in my M40 E30, T shape idle regulator valve just has 2 pin electrical wire, and the valve has screw on side to mechanically open or close the butterfly valve inside.
how to check above part to know the function good or bad
thanks b4

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW E30 3 Series Idle Speed Troubleshooting

[Wayne 962]

There are a few different versions of this valve, and I'm not 100% sure which one you have, but here's what I do for checking the valve. Firstly, I make sure the car has no vacuum leaks, as this will cause the valve to become somewhat useless (air will get into the system past the valve). Then, I disconnect the valve and watch the internal valve to make sure it opens and closes as you rev the engine. I also make sure I clean it out with some isopropyl alcohol and some q-tips. If I'm thinking about the valve that I think you have in your car, I believe that the screw on the side of the valve is to manually adjust the idle up or down when you're tuning the car.

- Wayne