Possible Cause & Correction

Check the following items:

• Check for binding throttle linkage.
• Check for leaking injectors. Perform INJECTOR BALANCE TEST in SYSTEM/COMPONENT TESTS article.
• Check Idle Air Control (IAC) system. Check for vacuum leak or high idle. Check for water contaminated fuel, correct fuel pressure or a restricted injector. Check for foreign material in IAC bore of throttle body. Check for proper connection of IAC valve electrical connector. Check for faulty crankcase ventilation valve. Check for failure of A/C compressor or relay.
• Check engine for overheating.
• Check for excessive use of fuel additives.