I have a lq4 setup with gmpp cnc ls3 heads, stock ls3 intake, holley 112-576 90mm cable driven throttle body. BT stage 4 cam. No mater what Ive tried this truck will idle at 1500rpm. There is no vacuum leak that Ive found. Nothing wrong with pcv system. Nothing wrong with tune that i could find. Does anybody have thoughts or ideas on what might be wrong with it?

 

For it to idle that high its getting air from somewhere. What are are you IAC steps at idle, I bet they are 0. If they are 0 the TB is open to much or you have a vaccum leak.