GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Tracker - 2WD 🢒 Engine 🢒 Engine Electrical 🢒 Poor Fuel Economy

Checks

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

Preliminary Checks
    • Refer to Symptoms - Engine Controls .
    • Check the air cleaner element for dirt or restrictions.
    • Visually and/or physically check the vacuum hoses for splits, kinks, and proper connections as shown on the Vehicle Emission Control Information label.
    • Check the owners driving habits for any of the following:
       - The A/C system or defroster mode is On all the time.
       - The tires are not kept properly inflated.
       - Heavy loads frequently being carried
       - Heavy acceleration and high speeds are common.
       - Frequent short trips
       - Prolonged periods of idling
       - Driving on unpaved, dirt, and rough roads
    • Suggest that the owner refill the fuel tank and recheck the fuel economy.

Fuel System Checks
    • Check the type, quality, and alcohol content of the fuel. Oxygenated fuels have lower energy and may deliver reduced fuel economy. Refer to Fuel System Specifications and Alcohol/Contaminants-in-Fuel Diagnosis .
    • Check for the correct fuel pressure. Refer to Fuel System Diagnosis .
    • Check the fuel injectors for proper operation. Perform the Fuel Injector Coil Test Procedure and the Fuel Injector Balance Test Procedure. Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) and to Fuel Injector Balance Test with Special Tool .

Ignition System Checks
    • Check for the correct ignition timing. Refer to Ignition System Timing Adjustment .
    • Check the spark plugs for correct operation and performance. Refer to Spark Plug Inspection .

Cooling System Checks
    • Check the engine coolant level.
    • Check the engine thermostat for always being open or for the wrong heat range. Refer to Thermostat Diagnosis and Engine Fails To Reach Normal Operating Temperature in Engine Cooling.

Additional Checks
    • Check the transmission shift pattern and the clutch adjustment.
    • Check for dragging brakes.
    • Check for uneven or premature tire wear. A suspension misalignment can cause a loss of fuel economy. Refer to Wheel Alignment Measurement in Suspension.
    • Verify that the tires and wheels are similar to OEM. Wide performance tires create more drag and taller tires can cause odometer discrepancies.
    • Check the exhaust system for a possible restriction.
    • Check for a green engine. The fuel economy may not be near expected levels until the engine has had 5 - 8 000 kilometers (3 to 5,000 miles) to break in.
    • Check the speedometer for the correct calibration. Refer to Speedometer and/or Odometer Inaccurate or Inoperative in Instrument Panel, Gages and Console.
    • Check the accuracy of the fuel gage. Refer to Fuel Gage Inaccurate or Inoperative in Instrument Panel, Gages and Console.
    • Check for add-on equipment like luggage racks and carriers. Wind resistance can lower fuel economy.
    • Check the Service Bulletins for any updates or information.