So my 87 Iroc 350tpi/automatic is acting odd. I can fire it up when it calms down will idle at about 1000rpm. After a drive of any amount of time it will idle at 2000k When put in park or neutral. And will stay there unless a quick touch on gas pedal. After that it will drop down to 1000 again, if you touch gas again it goes back 2 grand and stays there like before.



Not sure whats causing this. Also have a issue with starting. Some days it kicks right over other days it acts as if its carbed.

 

Lots of info on here pertaining to this common issue.

For starters, check for codes, and then try this procedure "TO A TEE."

https://www.thirdgen.org/newdesign/tech/tpimod2.shtml