Poor Fuel Economy
- Check for vacuum leaks.
- Check ignition system. See F - EEC BASIC TESTING article in the ENGINE PERFORMANCE Section.
- Check air intake system. Also, ensure throttle plate and linkages operate properly.
- Check fuel delivery system. See I - EEC SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
- Perform QUICK TEST. See G - EEC TESTS W/CODES article in the ENGINE PERFORMANCE Section.
- Check EGR system. See I - EEC SYS/COMP TESTS and G - EEC TESTS W/CODES articles in the ENGINE PERFORMANCE Section.
- Check cooling system thermostat.
- Check for slipping clutch.
- Check for dragging brakes.
- Check odometer calibration.
- Vehicle load, driving habits, road and weather conditions can also effect fuel economy.
- Check for restricted exhaust system.
- Check engine compression. Check engine mechanical condition. Check intake manifold, manifold gasket, camshaft and valves.