Racing Idle

[white00GT]

Ok I pulled my IAC valve off and cleaned it. It didn't seem like it was all that dirty, but I do have a some questions about it.

On the top of the IAC valve there is the little black cap type thing. Well Some how mine popped off or something happened but I can't remember so I just put a cap on the top of it to cap it off.

Should I have done this or should I get another one of those black little cap thingys to put back on it. When I had the IAC valve off I took the plug off that I put on it and blew through it. All it is is just a open little hole. This is one thing that makes me thing I should get another one of those caps because I don't remember the black cap fitting tight, I think I just remember it kinda floating around on the tube

Also, how does it work? looking inside of it you can see what looks to be a plunger of some sort. I tryed to test it by plugging it in and turning the ignition on but not starting the car. You can feel it click like it is going to do something but it acts like it's stuck.

Is it stuck, should it move?