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 at start of "Symptoms".
^ 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.

ADDITIONAL CHECKS
^ CHECK: PCM grounds for being clean, tight and in their proper locations. Refer to PCM wiring diagrams.
^ CHECK: EGR operation EGR valve may be open or partly open all the time. Refer to CHART C-7Chart C-7 EGR System Check.
^ CHECK: Generator output voltage. Repair if less than 9 volts or more than 16 volts.
^ CHECK: Exhaust system for possible restriction. Use CHART B-1B Charts.

- Inspect exhaust system for damaged or collapsed pipes.
- Inspect muffler for heat distress or possible internal failure.

^ CHECK: Torque Converter Clutch (TCC) for proper operation.

ENGINE MECHANICAL
^ CHECK: Engine valve timing and compression.
^ CHECK: Engine for correct or worn camshaft.

IGNITION SYSTEM
^ CHECK: Knock Sensor (KS) system for excessive spark retard activity. Refer to CHART C-5.Chart C-5 Knock Sensor (KS) System Check Use Tech 1 scan tool.
^ CHECK: Secondary voltage using a shop oscilloscope or a spark tester J 26792 (ST-125), or equivalent.

FUEL SYSTEM
^ CHECK: Restricted fuel filter.
^ CHECK: Fuel pressure, use CHART A-7.Related Tests, Information and Procedures
^ CHECK: Contaminated fuel.
^ Perform the "Injector Coil/Balance Test.Chart C-2A Fuel Injector Balance Test" Use Chart C2-A.