GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 Sonoma Pickup - 4WD 🢒 Engine 🢒 Engine Controls - 2.2L 🢒 Lack of Power, Sluggishness, or Sponginess

Checks

Action

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

Preliminary Checks
    • Refer to Symptoms .
    • Search for service bulletins.
    • Compare the customer's vehicle to a similar vehicle. Make sure the customer's vehicle has an actual problem.
    • Inspect the air cleaner filter for dirt or being plugged.

Fuel System Checks
    • Test the system fuel pressure. Refer to Fuel System Diagnosis .
    • Test the fuel injectors. Refer to Sequential Multiport Fuel Injector Balance Test .
    • Test for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Inspect for a restricted fuel filter.
    • Inspect items which can cause an engine to run rich (Long Term FT is significantly in the negative range). Refer to Diagnostic Aids for DTC P0172 Fuel Trim System Rich .
    • Inspect items that can cause an engine to run lean (Long Term FT is significantly in the positive range). Refer to Diagnostic Aids for DTC P0171 Fuel Trim System Lean .

Sensor/System
    • Using a scan tool, monitor KS system for excessive spark retard activity. Refer to DTC P0325 Knock Sensor (KS) Circuit .
    • Test for proper operation of the MAP sensor.
    • Test for proper operation of the TP sensor.
    • Inspect for a restricted air intake system.

Ignition System
    • Test for proper ignition voltage output with the J 26792 Spark Tester or equivalent.
    • Inspect the spark plugs for the following conditions:
       - Wet or fuel fouled
       - Cracks
       - Wear
       - Improper gap
       - Burnt electrodes or heavy deposits
    • If the spark plugs are fuel or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.
    • Inspect the ignition control module (ICM) for proper ground connection.
    • Inspect the ignition coils for cracks or carbon tracking.
    • Inspect the spark plug wires for proper resistance and condition.

Engine Mechanical

Inspect the engine for the following engine mechanical problems:

    • Low compression, refer to Engine Compression Test in Engine Mechanical
    • Correct valve timing, refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection in Engine Mechanical
    • Leaking cylinder head gasket, refer to Engine Compression Test in Engine Mechanical
    • Worn or a incorrect camshaft, refer to Camshaft and Bearings Cleaning and Inspection in Engine Mechanical

Additional Checks
    • Test for proper operation of the TCC. Refer to Torque Converter Diagnosis Automatic Transmission.
    • Test the exhaust system for a possible restriction:
       - Inspect the exhaust system for damaged or for possible collapsed pipes.
       - Inspect the muffler for heat distress or for possible internal failure.
       - Inspect for possible plugged Three-Way catalytic converter. Refer to Restricted Exhaust System Check .
    • Inspect the vacuum lines for kinks or leaks.
    • Test the generator output voltage. Repair the generator if the output voltage is less than 11 volts or more than 16 volts.
    • Test the A/C system operation. The A/C clutch should cut out at the wide open throttle (WOT) position.
    • If all procedures have been completed and no malfunctions have not been found, review and inspect the following items:
       - Visually and physically inspect all electrical connections within the suspected circuit and/or systems.
       - Scan tool data.