Poor Fuel Economy

DEFINITION:
From an actual road test the measured M.P.G. is noticeably lower than expected. At one time the fuel economy for this vehicle was at a greater average than current measurement.




SYSTEM OR COMPONENT TO CHECK ACTION

FUEL CHECK: ^ FUEL TYPE, quality and alcohol content.
^ FUEL PRESSURE


IGNITION CHECK: ^ SPARK PLUGS. Remove spark plugs,
check for wet plugs, cracks, wear improper gap,
burned electrodes, or heavy deposits.
Repair or replace as necessary.
^ IGNITION WIRES for cracking, hardness, and
proper connections.
^ IGNITION TIMING.



COOLING CHECK: ^ IGNITION For obvious overheating problems.
^ IGNITION Low engine coolant level and leaks.
^ IGNITION Water pump operation, loose belts
^ IGNITION Restricted air flow to radiator or restricted coolant flow.
^ IGNITION Faulty or incorrect thermostat.
^ IGNITION Correct coolant solution - should be a 50/50
mix of anti-freeze (coolant) and water.
^ IGNITION Fan operation (electric or belt driven).





MECHANICAL - ENGINE/TRANSMISSION CHECK: ^ IGNITION Transmission shift pattern.
^ IGNITION TCC operation. A "Scan" tool should indicate an
rpm drop when the TCC is commanded "ON."
^ IGNITION For proper calibration of speedometer.
^ IGNITION For dragging brakes.
^ IGNITION For proper tire inflation.
^ IGNITION Engine compression.