Have a 97 ZR2 Manual Trans and keep getting code p0507..replaced iac valve,turn off code,drive for about 80 or so miles and Service Engine light re-appears same code. Checked valve and connection lead.. all good...what am I missing? It all started when Icleaned the intake body with carb cleaner. I took oldiac and replaced it and cleaned the bore..should work..but can't shake the Engine light reappearing...any ideas??

 

The following items could cause this
An IAC valve which is stopped and cannot respond to the VCM
A throttle stop screw which has been tampered with
A damaged throttle or linkage
A slow, unstable, or fast idle may be caused by a non - IAC valve system problem that cannot be overcome by the IAC valve. tHE Out of range control IAC scan tool counts will read above 60 if the idle is too low and zero if the idle is too high.

 

Well...checked out things that you suggested, pulled IAC valve out and checked function..let idle re-set and drove...seemed good for a while..about 150 miles later "Engine" light back on..same code..could it be vacumn lines? Which test is it specificly on the analyiser for the valve fuction..mines is an Actron 9185 and should have all the functions. Thanks!! TR