Oscillating Idle...help!

[Rivan16]

My idle started ocsillating...again...it will go to about 1400RPM and then start droping to 900RPM constantly. I've had it before and was able to "fix" it for while, but it is back again. I know this is caused by air trapped inside the Idle air control valve which is made to work off coolant/water temperature and not air temperature as it passes thru it.
I "created" an air diverter in hope to trap possible air bubbles off a "T" and into a hose going higher than the valve is located. I think I'm right in there with the idea but it is not working...
The other end goes to a drain cock which I open from time to time in order to let the air out. But not the result I was hoping for...I've uses one of those 1/2 gallon funnels, ran at idle for 45+ minutes in hopes to drain the air; let stand after 45 minute idle with funnel still on hoping for drainage; open drain cock and placed inside jug with some coolant inside which was siphened during the engine off cycle...

If there's anyone who understands the cooling system better than me and could guide me I will trully appreciate it.

I thought of by passing the valve but that would leave me with a hi-RPM iddle and will not control during AC operations. This is a show car, not track car and AC is a most in the state on Florida.

Anyone...anyone!?!?!?!

[assassin10000]

It may not be air, it may be corrosion build up in the valve preventing it from moving as it should. Or since it is a wax-pellet, it may be worn out (like a t-stat will).

You can try removing the IACV and letting it soak overnight in CLR, that's worked in the past for others.

Andrew