October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.
Rough/Unstable Idle
- Use sound amplification tool to verify operational noise coming from fuel injector(s).
- Ensure fuel system pressure is correct.
- Check PCV system for restrictions.
- Check coolant thermosensor for correct resistance.
- Check air valve or ISC valve for malfunction.
- Check connections at airflow meter or throttle body.
- Check for cracks or poor connections at airflow meter or throttle body.
- Check O2 sensor for 0-1.0 volt output while changing engine RPM up and down.
- Verify throttle position sensor has correct adjustment and resistance value.
- Check for purge valve malfunction.
- Check for poor connections at airflow meter or throttle body.