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 vehicle at one time, as previously shown by an actual road test.

Preliminary Checks
^ Perform the visual/physical checks as described under Diagnostic Notes in this section.

^ CHECK: Visually (physically) check: Vacuum hoses for splits, kinks, and proper connections as shown on "Vehicle Emission Control Information" label.

^ CHECK: owner's driving habits.
- Is A/C "ON" full time (Defoster mode "ON")?
- Are tires at correct pressure?
- Are excessively heavy loads being carried?
- Is acceleration too much, too often
^ CHECK: Check air cleaner for dirt or being plugged.

Ignition System
^ CHECK: Ignition timing. Refer to "Vehicle Emission Control Information" label.
^ CHECK: Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear. improper gap, burned electrodes, or heavy deposits. Repair or replace as necessary.

Cooling System
^ CHECK: Engine coolant level.
^ CHECK: Engine thermostat for faulty part (always open) or for wrong heat range.

Engine Mechanical
^ CHECK: Compression.

Additional Checks
^ CHECK: TCC operation.
^ CHECK: For exhaust system restriction.
^ CHECK: Induction system and crankcase for air leaks.
^ CHECK: For dragging brakes.