Excessive Idle 2000 P71

My 2000 P71 is idleing excessively high. Here's the background.

I recently changed to left cylinder head. The timing chain and components were in almost new condition. I installed the original camshaft and followers on the replacement cylinder head. It still has the plastic manifold also.

I have detected a leak in the intake manifold to cylinder head mating surface. Three times I reinstalled the manifold using new gaskets. The first two times I used felpro gaskets from oreily, the last time i used victor gaskets from napa. The lease was diminshed using the vicotr gaskets but still leaks. Is this the only cause for my excessive idle speed? Will replacing the IAC solve the problem?

It idles long and strong in all gears. I haven't put it on the road yet so I don't know how it will run under load.

Any suggestions appreciated.

Use the FACTORY Ford gaskets, they are about $6/each.

The IAC might be an issue, but even if you change it, you will still have a vacuum leak.

MODMECH, you are quick. Headed to the store right now. Will keep you posted

Changed the gaskets, leak was diminished. Now I will take the car to a dealer to replace the intake manifold. I think that may be the problem. Besides, I understand that there is a recall on the plastic manifolds anyway. They should replace mine for next to free.

Any other ideas for me???? Anyone...

You may also want to look at the AIC valve. Had some problems with mine, replaced it one I had lying around and the car was idling at about 2500rpm. Replaced it with the original after a good cleaning and the idle returned to normal

Thanks Radio, I'll hit the car tonight!! Here's an update...

The dealer claimed that the cant change the intake manifold until it develops a leak. I looking into that. Tonight I goint to try high temp copper plus gasket maker between the manifold gasket and the head. One of the dealer mechanics claims that the head was not machined properly, causing a leak. Ideas???

Regarding the IAC valve. All that I have read said that if it was failing there would also be noise associated with it. Is this always true because there is no noise comming from my IAC valve.

The dealer mechanic is feeding you a line of Hooey.

Use the FACTORY gaskets and the intake will NOT leak.

The IAC will also cause idle problems, but typically a rolling idle, and NOT excessively high idle.

I did use factory gaskets on my last attempt. But the leak was not totally eliminated. Last night I reinstalled the factory gasket coupled with some "copper plus" gaslet maker. If doesn't get rid of the leak than something else MUST be wrong. Also, before I close everythingup I will flush the cooling system for 10 minutes.