hi idle problem

I have a high idle problem with my 2000 venture extend van; Here is some history:
Van has had the problem with the bucking transmission. Shut the vehicle off, and then it acts fine. I know I need to have the transmission modules replaced. However, this problem has stopped for some time.
Now the vehicle idle increases to 3k or higher. I noticed that most of the time it will idle normal when I start it, but will increase in idle when I shift into gear.
I’ve shot W2 along the hoses to find a vacuum leak, but found nothing.
Repair History: I did the lower intake manifold gasket myself last year and replace plugs & wires, water pump, injector o-rings, and a few other things. I’ve had the dealer replace the IAC two times.
Because the high idle occurs when I shift it into gear, could it be the modules on the transmission?
Any other thoughts?

Just a thought, do you have a "Service Engine Soon" light on?

I would tend to think that the trouble is coming from your transmission, based on your comments.

Toni.

No Check engine light. I'm going to try to replace the PCV valve from the dealer - this is cheap first step. Going to get it from the dealer.