For it to be idling that high, (if not the FITV, which you've ruled out) I'd think it would have to either be a a vacuum leak or the throttle plate is actually sticking open - I'm not saying that's likely, but it's pretty high, it must be getting significantly more air than it's supposed to. Not necessarily through a vac. line itself, just a leak somewhere letting air into the manifold or even between the manifold and head.
I've yet to have to do this, but you can spray starter fluid around the vac lines and manifold, if the revs go up when you spray a certain area, you've found the leak.

I'm assuming your Electronic Air Control Valve is constantly closed (or as much as it can close) trying to lower the idle, so it's not making adjustments and making the idle jump or fluctuate like often happens.