I had a similiar issue on my 93 voyager with 200K, 2.5L engine. I replaced the AIS motor and throttle position sensor. While I was doing this, I discovered that the wire leading from the AIS motor had lost most of it's insulation in some places and the wires were touching. I took the wiring harness off, wrapped each wire in heat resistant electrical tape, and replaced it. I disconnected the battery to reset the computer. It has idled normally since that time.
What mine had been doing was idling pretty high, while I was driving, and then when I pulled in to park it and put it in park it revved pretty high. When I gave it a little gas it revved up and stayed there.
So if you haven't got it fixed yet, you may look at the wiring harness around the AIS, and replace the AIS. That's a cheap fix if it works.
Wednesday, October 24th, 2007 AT 1:56 PM