this one is strange to me... as im driving my 97 z28 and when i come to a light or a stop with the clutch in as i am coming to a stop the ideal is high around 1500-2000 and it will slowly come down as i sit down to its normal
any ideas on what this me be ??????

 

dirty throttle body, iac valve.

 

In addition to the above suggestions, check the throttle linkage. May not be closing fully, causing it to idle high.