Herk wrote:If the IAC does in fact go all the way to zero "0" with the engine idling, you either still have a vacuum leak or the throttle plates aren't closing all the way. Double check your throttle linkage (unhook from TB when setting idle), and if the idle stop screw has been messed with, back it off a bit. But before you go much farther figure out why the engine was idling so low in the first place. It may be the IAC or it may be the computer. What RPM is it supposed to be idling at? Got a junkyard IAC handy?
The screw isn’t to adjust the idle.