High Idle 2.4 Fuel Injected

Ok, I have looked, Searched, Cussed, and tried everything I know to do. Now I cant seem to find a "sticky" to point me in the right direction.

On my 1990 MMM, It has started to high idle. Not throwing any codes. Fresh MAF Installed few weeks back.

1: I have unhooked the battery for 10 minutes, I then connected the battery and let the truck idle for 10minutes to "set" the standards. Didnt work..
2: I checked the Idle adjustment screw, its not even touching.
3: I have checked the cable, It has some slack.
4: I have checked for vaccum leaks.
5: If I disconnect the IAC the truck idles down, (( Is there an adjustment I am missing on the IAC? ))
6: Checked the butterfly and no blockage there.
I can't seem to find what is causing the problem.
HELP

Bueller, Bueller, Bueller. .........

dang!....i know you mentioned "checked vacuum leak" (& there are so many & can be very tricky/time consuming)....but is there anything else on the intake side that could be suspect..ie-tired gasket/loose bolt?..never know what the previous owner decided to "fix".

Throttle Position Sensor...maybe check that.

Ragragtimetime I am going to "Go Over" everything again. Royster, Your Da' Man I was hoping to chime in. I checked it, Took it off and it still idles high. I have a feeling that its the IAC because when I disconnect it, the truck idles down where I can adjust it with the idle screw. I cant find an adjustment on it though. Looks like the spare head and intake I picked up are about to be scavenged for parts. Is this a normal wear item?

I know nothing about the idle servo, because I haven't had to deal with it...yet. I do know my idle problems were pretty much solved when I replaced the TPS (fuel injected) and I adjusted the throttle cable to book specs.

Thanks for your vote of confidence :)