GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Sonoma Pickup - 2WD 🢒 Engine 🢒 Engine Controls - 2.2L (L43) 🢒 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 - Engine Controls .
    • Search for service bulletins.
    • Inspect and compare the customers vehicle to a similar vehicle. Make sure the customers vehicle has an actual problem.
    • Inspect the air cleaner filter for dirt or restrictions.

Fuel System Checks
    • Inspect the system fuel pressure. Refer to Fuel System Diagnosis .
    • Inspect the fuel injectors. Refer to Fuel Injector Balance Test with Tech 2 .
    • Inspect items which can cause an engine to run rich--Short term FT is significantly in the negative range. Refer to Diagnostic Aids for DTC P0172 .
    • Inspect items that can cause an engine to run lean--Short term FT is significantly in the positive range. Refer to Diagnostic Aids for DTC P0171 .

Sensor/System
    • Use a scan tool in order to monitor knock sensor (KS) system for excessive spark retard activity. Refer to DTC P0325 .
    • Inspect for proper operation of the manifold absolute pressure (MAP) sensor.
    • Inspect for proper operation of the throttle position (TP) sensor.
    • Inspect for a restricted air intake system.

Ignition System
    • Inspect for proper ignition voltage output with a J 26792 Spark Tester or equivalent.
    • Inspect the spark plugs for the following conditions:
       - Wet or fuel fouled
       - Cracks
       - Wear
       - Improper spark plug gap
       - Burned 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 2.2L (L43).
       - Correct valve timing
       - Leaking cylinder head gasket
       - Worn or a incorrect camshaft
    • Refer to Symptoms - Engine Mechanical in Engine Mechanical 2.2 L (L43).

Additional Checks
    • Inspect for proper operation of the torque converter clutch (TCC). Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transmission.
    • Inspect the exhaust system for a possible restriction:
       - The exhaust system for damaged or for possible collapsed pipes
       - The muffler for heat distress or for possible internal failure
       - Possible plugged TWC--Refer to Restricted Exhaust in Engine Exhaust.
    • Inspect the generator output voltage. Repair the generator if the output voltage is less than 11 volts or more than 16 volts.
    • Inspect 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 been found, review and inspect the following items:
       - All electrical connections within the suspected circuit and/or systems
       - Scan tool data