Lack of Power, Sluggishness, or Sponginess

DEFINITION: Engine delivers less than expected power.

^ Verify customer's vehicle has an actual problem by comparing it to a similar vehicle.

Check:
^ Air filter for restriction
^ Restricted fuel filter, contaminated fuel or improper fuel pressure
^ Exhaust system for restriction
^ Generator charging output voltage. Repair if less than 13 volts or more than 16 volts with all accessories off.
^ Verify engine has no mechanical knock or spark knock. If knock is present, engine timing will be retarded and loss of power will result. (View spark modifiers on Scan tool.)
^ Engine valve timing, compression or worn camshaft
^ Worn spark plugs.