Lack of Power, Sluggishness, or Sponginess

Checks	Action
DEFINITION: The engine delivers less than expected power. There is little or no increase in speed when partially applying the accelerator pedal.
Preliminary Checks	Refer to Symptoms - Engine Controls . Compare the vehicle with a similar unit. Make sure the vehicle has an actual problem. Remove the air filter and check for dirt, or for air ducts being plugged. Replace as necessary. Check for a proper transmission shift pattern and down shift operation. Check the engine oil level and quality.
Fuel System Checks	Check the fuel supply to the injection pump and the fuel return from the injection pump. Refer to Fuel System Diagnosis . Check the fuel pump operation. Check for malfunctioning fuel injection nozzles. Check the top dead center (TDC) offset value. Refer to Fuel Injection Pump TDC Offset Adjustment .
Exhaust System Checks	Check the exhaust system for a possible restriction. Refer to Restricted Exhaust . Inspect the exhaust system for leaks.
Air Intake System Checks	Check for an air leak or restriction in the air inlet ducts or the intake manifold. Check for a worn or damaged turbo charger turbine wheel, shaft or compressor wheel.
Engine Mechanical Check	Check the engine for the following conditions: Low compression. Refer to Engine Compression Test in Engine Mechanical 6.5L. Improper valve timing Improper or worn camshaft
Additional Checks	Check the control module grounds for being clean, tight, and in their proper location. Check the torque converter clutch (TCC) operation. Refer to Torque Converter Diagnosis in Automatic Transmission-4L80-E. Check the A/C operation. Refer to CCOT Air Conditioning (A/C) System Diagnosis. Check the generator output voltage. Repair if less than 9 volts or more than 16 volts.