Okay, I found out *all* the extra air for the high idle is coming through the idle bypass circuit. The brand new idle control valve is doing something extremely sinister- it randomly decides what speed the idle should be, and it does this even when the 4 pin plug is disconnected!!! Grrrr.
So each time I disconnected a component (EGR, TPS, PCV) it would go to a normal idle for a few minutes, hours, even days.... then go back to a completely random high idle. (though it is a bit temperature related)
Therefore I plugged the idle hole in front of the throttle butterfly valve- thus taking the entire idle circuit completely out of the equation. Now it never idles above 800 rpm. So I can now drive the car, but not very well when it is still cold.
I took my analog meter to check the 4 wire inputs to the idle control valve. There were three things which are very strange:
1) none of the 4 wires is a ground
2) with the engine off, each of the 4 wires measure about 20k ohms
3) when the engine is warm, all 4 of the wires would "pulse" between 1v and 11v at a one second interval
So is this the normal input on the 4 wires? HELP!
Problem Solved!!!
Finally resolved this issue by buying a used throttle body (which included the TPS and IAC) for $45.
http://car-part.com/
Found out both of the new IACs I installed were bad and had failed in the same manner as the original IAC.
What are the odds of that happening?
So I chased this problem for 6 months.... when the first component I replaced should have fixed it.
Lesson learned: the $12.50 Amazon/Made in China IAC was not much of a bargain.
Thanks for all the help.