Poor Fuel Mileage
- Ensure idle speed, base timing and timing advance are set to specifications.
- Check cold start valve for leaking (engine warm).
- Check fuel system and control system pressure. Replace pressure regulator if necessary.
- Check thermo time switch operation.
- Check airflow sensor voltage output.
- Check air induction system for leaks.
- Check fuel injector operation.
- Check coolant temperature sensor operation.
- Check Oxygen (O2) sensor operation.