Poor Fuel Economy

Fuel economy is noticeably lower than expected. Customer should drive vehicle and note miles per gallon decrease.

POSSIBLE CAUSE ACTION


Incorrect initial timing Check base timing.
SEE Ignition System/ ADJUSTMENT PROCEDURES.

Check CAM timing.

Incorrect spark advance Check spark controls.
SEE Ignition System/ TIMING SPECIFICATIONS

Incorrect Air-Fuel mixture Check fuel pressure.
Check O2 sensor.
Perform injector balance test (MPI).

EGR malfunction Check EGR system.

Poor or contaminated fuel Recommend higher grade fuel