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 careful visual/physical checks as described in "PRELIMINARY CHECKS". Testing and Inspection
^ 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 (Defroster mode "ON")?
- Are tires at correct pressure?
- Are excessively heavy loads being carried?
- Does driver accelerate hard often?

^ Check air cleaner fllter for dirt or being plugged.

IGNITION SYSTEM
^ Check ignition system secondary components for arcing, excessive resistance, cracked, worn, fouled, improperly gapped, or incorrect type spark plugs.

COOLING SYSTEM
^ Check engine coolant level
^ Check engine thermostat for faulty part (always open) or for incorrect heat range.

ENGINE MECHANICAL
^ Perform cylinder compression test.

FUEL SYSTEM
^ Fuel pressure.Refer to "DIAGNOSTIC CHARTS/A-CHARTS/CHART A-7 FUEL SYSTEM DIAGNOSIS". Related Tests, Information and Procedures

ADDITIONAL CHECKS

^ Check exhaust system for possible restriction. Inspect exhaust system for damaged or collapsed pipes, heat distress, or plugged catalytic converter. Refer to "DIAGNOSTIC CHARTS/CHART B-1 RESTRICTED EXHAUST SYSTEM CHECK.
^ Check for proper calibration of speedometer.
^ Check induction system and crankcase for air leaks.
^ Suggest driver read "Important Facts on Fuel Economy" in "Owner's Manual."