Lack of Power, Sluggishness, or Sponginess. Pontiac Sun Runner - 4WD (Canada) 1997

For 1990-2009 cars

#### 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 Powertrain On Board Diagnostic (OBD) System Check .

• | Refer to Symptoms .

• | Compare the customer's vehicle with a similar unit in order to determine if the customer has an actual problem.

• | Remove the air filter element and check for dirt or restrictions.

• | Check the transmission shift pattern and down shift operation.

Fuel System Checks

• | Check for a restricted fuel filter or incorrect fuel pressure

• | Check the fuel injectors. Perform the Fuel Injector Coil Test Procedure and the Fuel Injector Balance Test Procedure. Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) and Fuel Injector Balance Test .

• | Check for contaminated fuel.

Ignition System Checks

• | Check for the proper ignition voltage output with a spark tester (J 26792 or equivalent).

• | Check the ignition timing and proper operation of the ignition control system. Refer to Ignition Timing Procedure.

Exhaust System Checks

• | Check the exhaust system for a possible restriction.

• | Inspect the exhaust system for damaged or collapsed pipes. Inspect the muffler for heat distress or a possible internal failure.

Additional Checks

• | Check the PCM grounds for being clean, tight, and in their proper locations. Refer to PCM Wiring Diagrams.

• | Check the EGR Valve for excessive flow or sticking open. Refer to Exhaust Gas Recirculation (EGR) System Diagnosis .

• | Check the generator output voltage.

Engine Mechanical Check

• | Check for any of the following engine mechanical problems:

- | Low compression

- | Incorrect valve timing

- | Incorrect or worn camshaft

• | Refer to Engine Mechanical.