Lack of Power/Sluggish/Spongy/Stumble

Definition: Engine delivers less than expected power. Little or no increase in speed when accelerator pedal is pushed down part way.

PRELIMINARY CHECKS

^ Perform the careful visual/physical checks as described in DIAGNOSTIC NOTES.
^ Compare customer's vehicle to similar unit. Make sure the customer has an actual problem.
^ Remove air filter and check air filter for dirt, or for being plugged. Replace as necessary.

FUEL SYSTEM

^ CHECK: Restricted fuel filter.
^ CHECK: Fuel pressure, Related Tests, Information and Procedures
^ CHECK: Contaminated fuel.

IGNITION SYSTEM

^ CHECK: Secondary voltage using a spark tester J 26792 (ST-125), or equivalent, to check for a weak coil.
^ CHECK: Knock sensor system for false retard due to mechanical noise.

ADDITIONAL CHECKS

^ CHECK: PCM grounds for being clean, tight and in their proper locations. Refer to PCM wiring diagrams.
^ CHECK: Generator output voltage. Repair if less than 9 or more than 17 volts.
^ CHECK: Exhaust system for possible restriction. B Charts
- Inspect exhaust system for damaged or collapsed pipes.
- Inspect muffler for heat distress or possible internal failure.
^ CHECK: Shift solenoid system and Torque Converter Clutch (TCC) for proper operation. Chart C-8A Torque Converter Clutch (TCC) Diagnosis
^ CHECK: For PCM DTC 68 set. If so, vehicle may be operating in "Power Management" mode. DTC 68

ENGINE MECHANICAL

^ CHECK: Engine valve timing and compression.
^ CHECK: Engine for incorrect or worn camshaft.