Trying to diagnose a bad IAC with no service info - frustrating as hell!

All my testing has narrowed it down to the IAC. What I want to know is, as the unit is sitting in my hand, should I be seeing right inside the unit through the port that's pointing down in the last pic? From what I've been reading, this should be closed off with no power applied. Also, this unit has 2 pins - not 3 - for the electrical connection. When I energize the unit, the shutter flips around briefly, and can barely be seen through the port. I can blow air through it regardless of having 12v at the pins, or 0v at the pins.

Thing looks fairly new, and is extremely clean inside as you can see. I sprayed some silicone spray in there to lube and clean things up a bit (not that it needed it - just in case it may have been sticking). Anyone ever looked inside one of these, or better yet, anyone have a known good one laying around to look at? I suspect I should be seeing the shutter closing off that port when there's no voltage applied to the pins. I just need 100% confirmation of this.

Any and all info will be greatly appreciated!


Looking through the port with the arrow on it in the last pic

Looking through the port with the arrow on it in the last pic

Prior photos taken inside the downward-facing port in this pic.

 

Forgot some key info here - VEHICLE: '95 Volvo 940 wagon 2.3L 4-cylinder, Bosch system.

 

Whelp, looks like I'm the only one who knows the answer to this question now. Hopefully this will help someone else down the line who's attempting to keep these 940's on the road.

I hate winging parts at something without thorough troubleshooting, and being 200% sure that a new part will fix the problem. Without service info, I took a chance, based on my limited testing and observation of the old part, and purchased a brand new Bosch idle air control valve. Lo and behold, the shutter is 90% CLOSED on the new one! There's just a tiny opening to the left - 90% of the opening is blocked by the shutter. Exactly what I suspected. Made the right call, and for that I'm happy.

Here's pictures of the new unit taken in the exact location of the old unit in the post above (down the tube with the arrow on it).


New Bosch idle air control unit

Shutter CLOSED at rest (no voltage applied)

Small opening to the left for correct default idle speed