Poor Fuel Economy

DEFINITION: Fuel economy, as measured by an actual road test, is noticeably lower than expected. Also, economy is noticeably lower than it was on this car at one time, as previously shown by an actual road test.

Visually check vacuum lines for cracks, loose connections, or damage. Check fuel delivery system for obvious leaks. Verify the actual fuel mileage.

CHECK:

- Air cleaner filter to be clogged, or air inlet tube blocked.
- Ignition timing.
- Wrong spark plugs, or worn, damaged spark plugs.
- Poor fuel quality.
- Restricted exhaust.
- Transaxle operation, i.e.; slipping, not shifting, wrong shift points (M/T) clutch slipping.
- Brakes not fully releasing.
- Wrong or faulty thermostat.
- Wrong tire size or improper tire pressure.
- EGR valve operation.
- EPI system.
- PCV valve operation.
- ESA system.
- High idle.
- Faulty Throttle Switch.
- Faulty MAT sensor signal.
- Faulty Coolant Temperature Sensor (CTS) signal.
- Faulty ECM.