Idle Troubles

[JDID]

Truck is a 97 Chevrolet, 4.3 5 speed

 

As long as the truck is sitting still, there isn't really a problem, but after I start rolling, the idle speed gets a little wierd. When I clutch, or ride it in Neutral, the idle speed goes up to 1000-2000 rpm. I'll let off the gas and when I press in the clutch, it idles back up before I can get to the next gear. When coasting to a stop in neutral or clutched, the idle speed goes up and down until I come to a stop, then it drops to normal.

 

Thoughts or Opinions????

[99-2door]

Idle air control.