Lack of Power, Sluggish, or Spongy

DEFINITION
Engine delivers less than expected power. Little or no increase in speed, when accelerator pedal is partially applied.

PRELIMINARY CHECKS
- Refer to Important Preliminary Checks. Preliminary Checks
- Compare customers vehicle with a similar unit. Make sure the customer has an actual problem.
- Remove air filter and check for dirt, or for air ducts being plugged clean or, replace as necessary.
- Transmission shift pattern and down shift operation Refer to Functional Test Procedure/Transmission Control Systems. Testing and Inspection
- Check fuel quality refer to fuel specific gravity check in Fuel Systems.
- Check engine oil level and quality.

FUEL SYSTEM
- CHECK: Fuel supply to injection pump and fuel return from inspection pump. Refer to Fuel Systems. Fuel Supply Line
- CHECK: For faulty fuel injection nozzles. Refer to Fuel System. Testing and Inspection

EXHAUST SYSTEM
- CHECK: For restricted exhaust system. Refer to C-Charts / Restricted Exhaust System Check. Testing and Inspection


ADDITIONAL CHECKS
- CHECK: Control module grounds for being clean, tight, and in their proper location. Refer to Diagrams/Electrical. Diagrams
- CHECK: EGR operation for being open or partly open all the time. Refer to Exhaust Gas Recirculation (EGR). Testing and Inspection
- CHECK: Torque Converter Clutch (TCC) operation. Refer to Transmission Control Systems. Testing and Inspection
- CHECK: A/C operation. Refer to Diagnostic Charts.
- CHECK: Generator output voltage. Repair if less than 9 or more than 16 volts.

ENGINE MECHANICAL
- CHECK: Engine compression, valve timing, and for proper or worn camshaft. Refer to Engine/System Diagnosis.