Its higher on a cold start. Where is the IAC?

 

Can't say for certain but it's *usually* on the throttle body. If not there then it's on the intake manifold. It'll be after the throttle plate and before the plenum splits to the individual intake runners. However the fact that it idles higher on a cold start and then drops down to normal idle speed I'd say your IAC is working. I'd give another vote then for checking the throttle body. Especially if your PCV vents to the intake pre-throttle body.

 

Thanks ill look it over

 

Which one you found, LincolnsOnline? They are good for the Lincoln-specific stuff but may be somewhat slow to respond to your questions. For anything engine- and chassis-related go to GrandMarq.Net (aka GMN), tons of guys with all sorts of 5.0 fullsize cars there ranging from all-stock to weird transplants to autocross racers, stupid-good amounts of tech knowledge too.

 

The IAC is on the back side of the throttle body, it's a cylindrical thing the size of small bottle of pills and it has a 2-wire harness plugged into its end. To remove it you'll need a deep 8mm (or 5/16") 1/4"-drive socket, there are two bolts that hold it to the throttle body and the bottom one is kinda hard to see but easy to find by feel. Once off you can spray some carb cleaner in the air passages, you can also move the little valve in there by hand to make it easier to get the gunk out.