when i give her gas and imediatly let off or any time i let off the gas from a higher rpm, the motor waits about 2- 3 seconds before it idles down. it just runs on for a bit then idles down to base idle. totally lost on this one. TPS???

vehicle is 90 burb with 350 TBI

 

sounds like the IAC is dirty and getting sluggish and/or burning out... Try cleaning the threaded area on the pintle and make sure there arnt any heavy carbon deposits on it.

 

It's stock programming most likely. There is a LOT of throttle follower with stock calibration. It drives me nutz but some people with all stock motors don't mind it. It doesn't help that I've got a pretty wild motor combination vs lots of fellow TBI members.
It could be a stuck IAC but I doubt it if the idle is returning down to where it should be. Get a hold of a scan tool or use a laptop and winaldl to watch your IAC counts.

 

Mine does the same exact thing, when you pull up to redlight it will idle high and slowly come down to normal idle speed about 750 RPM is where it idles down to.