Another Iac Thread...

Yes, another one. Sort of. Well, I believe my IAC is sticking, it usually gives me a high idle and I've gone and checked for vacuum leaks finding nothing. It is a part store brand that is out of warranty, so I am thinking it is going to buy the farm here soon. Looking online there is a difference between IACs depending on the year of the car for all PI 4.6's. I'm running a Trickflow plenum/TB and bought the one that resembled closest to the OEM one when I replaced the OEM one. Is there any difference between the ones that have the black cap and ones that don't?

There is not much of a difference. Actually does not matter. Answer was actually having to do with my TPS settings in my tune. The tolerances were just out of whack and it didn't think the throttle blade was closing completely. My toner extended the tolerances and now all is well.