bad throttle body?

[jsmith]

87 T, has 135,000 miles on her, when you blip the throttle at idle it takes a long time for it to get back to idle almost like linkage is hanging up but even if you blip the throttle by hand right on the throttle body it still does same thing. Looked the linkage and exterior of throttle body over and everything looks fine, what should I look for as I check the inside of the throttle body. I am about to put her up for the winter and have many projects planned just wondering what the experts think and if anyone else has seen this? Are the bushings on the throttle blade worn? is there something else I should be looking at that can cause this? Havent opened it up yet but the linkage and throttle arm all seem to be O.K. Any thoughts, anyone? Thanks for the help guys it is much appreciated. Jeff

 

[chasmat2316]

I would look at the IAC!

 

[jsmith]

I have been chasing this for the summer and replaced the IAC with new, have reset and adjusted iac and tps numerous times and both are set within limits. with no help to my issue. Thanks for the thought though. Jeff

 

[Sleeper-6]

Sounds like it's working just as it should. if you have a scan tool, watch the IAC counts as the RPMs come down. you should see the counts step down in sync with the RPMs.