Ranger Throttle

I have a 04 Ranger with the 4.0, 6 cylinder engine. The problem is that the throttle sticks at around 2000 RPM at times. If I stop it goes back to idle. Ford has changed out the idle control device and it still happens at times. I can hit the throttle and it makes no difference. Also it sure would be nice if the engine didn't go to 2000 RPM on start up. Sure would appreciate any ideas on these problems.

Thanks
Vic : :banghead: