I have a '99 Taurus with the 3L Vulcan engine. Car has 106,000 miles on it. I love this car. Everything is fine on the car except the idle. When I first start the car it idles perfect. After driving for a few minutes I can feel the engine RPM's surging up(while in gear). If I put the car in neutral when driving, the idle speed goes up to 3000-4000 rpms. Tapping the gas does no good. If I have the car in gear and come to a stop light, put the car in neutral, the engine still races up, but slowly settles down to normal idle rpm's. The idle never goes below normal speed, it only races up. Has anyone had this problem before? If so how can I fix it? I am mechanicly inclined. Any suggestions would be appreciated! Thanks!

Idle Air Control Motor. It is probably sticking open.