Just wondering if anyone has experienced this. I have a 1997 f-150 4.6L supcab 4x4 WITH 5-SP. When I shift and push the gas pedal the engine acts normal but as I let off it maintains the rpms for a second or two before dropping back to idle-level rpms. Sometimes it takes like 30 seconds or better to drop off. I think there could be a number of possibilities
-a vaccum leak
-IAC motor
-TPS
-Sticky throttle cable/linkage

Anyone have/resolve this one before? It is just getting above 0 here so I may actually get motivated to look at it, but I thought I might cheat by picking your brains.

Thanks!

 

I would first clean the throttle body,and then the IAC.Usually,IAC will stick partially open,and cause a vacuum leak.This doesent sound like your problem.Needless to say,check for binding in the throttle cable as well.