Diagnostic Aids
WARNING: This page is about a different car, the 2000 Isuzu Hombre. However, it is still accessible from the selected car via links, so may be relevant.
Ensure throttle stop screw has not been tampered with. Check for stuck IAC valve or throttle linkage. Reset IAC using scan tool MISC FUNCTIONS. Check if fuel system is running too rich or too lean. Inspect throttle body bore for foreign material.