High Idle 92 Voyager

My Voayger gas a 2.5 L engine with a 5 speed transmission. It idles constantly at approx 2200 RPM... sometimes after a long drive it will increase idle speed slightly. I can find no vacuum leaks.
I changed the engine about 20,000 miles ago. It was doing the same thing with the previous engine. I also changed the throttle body.
Any ideas?

Regards,
Ken

Have your timing checked.
If the distributor or oil pump was removed from this motor at any time the timing may be off. This motor has the distributor running off of the oil pump instead of the cam. If the oil pump rotated a little before or during reinstalation the timing will off. I had the same motor (92 caravan 2.5 w 5speed manual trans) That is what happened to me when I installed a new oil pump. when i was done it would run extremely rich with no power. After two days of head scratching and sore scalp I figured I would move the distributor a little. It worked now it runs fine but idles high especially after coming off the highway the motor is racing. It will settle down a little after sitting a couple of minutes.
But I cannot move the dist anymore without taking it out and turning the oil pump to get the couple more degrees that need to get it right.