Hey everyone, I've been searching for a little over 2 hours and can't find a direct answer for my issue. I have a looping idle, it only seems to be in Neutral\Park, idles fine in gear. It starts out around 1500 rpm, then slowly drops to about 700 then jumps back up 1500. I've replaced the TPS (set at .97v), new ECT (old tested a little out of range), new ACT (old was caked in carbon), and I've switched the vacuum system over to rubber. I've cleaned the IAC, with no change, my meter shows it at 11 ohms (within Haynes spec). I unplug the IAC while it's idling and it drops down to ~600rpm, and whenever I rev it the rpms drop back to ~600 much, MUCH faster. I've read that when you turn the key to on (not run), the IAC should get 10.5volts, but mine gets 12v. I'm confused, do I need a new IAC? Is there something going on with whatever controls the IAC?

Thanks for any help