GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2002 🢒 Alero 🢒 Engine 🢒 Engine Electrical 🢒 Surges/Chuggles

Surges/Chuggles

Checks

Action

DEFINITION: Engine power variation under steady throttle or cruise. Feels like the vehicle speeds up and slows down with no change in the accelerator pedal.

Preliminary
    • Refer to Symptoms - Engine Controls .
    • Search for service bulletins.
    • Be sure the driver understands the transmission torque converter clutch (TCC), and the A/C compressor operation as explained in the owners manual. Inform the customer how the TCC and the A/C clutch operates.
    • Check the powertrain control module (PCM) grounds for the following conditions:
       - Clean connection
       - Tight connection
       - Proper location

Sensor/System
    • Check the oxygen sensor (O2S 1). The O2S 1 should respond quickly to different throttle positions. If not, check the O2S 1 for silicon or other contaminants from fuel or the use of improper RTV sealant. The sensor may have a white powdery coating. Silicon contamination causes a high but false O2S 1 signal voltage, rich exhaust indication. The powertrain control module (PCM) will reduce the amount of fuel delivered to the engine, causing a severe driveability problem.
    • Check for proper operation of the manifold absolute pressure (MAP) sensor. Refer to DTC P0105 .
    • Check for proper operation of the throttle position (TP) sensor. Refer to DTC P0105 .
    • Check for proper operation of the engine coolant temperature (ECT) sensor. Refer to DTC P0117 and DTC P0118 .

Fuel System
    • Check the fuel pressure. Refer to Fuel System Diagnosis .
    • Check for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Check the fuel filter for being plugged or restricted.
    • Ensure each fuel injector harness is connected to the correct fuel injector/cylinder. Refer to Engine Controls Schematics .
    • Check 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 .
    • Check 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 .

Ignition System
    • Check for proper ignition voltage output with the J 36012-A Ignition System Diagnostic Harness and J 26792 Spark Tester or equivalent.
    • Check the spark plugs for the following conditions:
       - Check for wet or fuel fouled spark plugs.
       - Check for cracks on the spark plugs.
       - Check for wear.
       - Check for improper spark plug gap.
       - Check for 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.
    • Check the ignition control module (ICM) for proper ground connection.
    • Check the ignition coils for cracks or carbon tracking.

Additional Checks
    • Check for proper operation of the TCC. Refer to Road Test in Automatic Transmission 4T40-E/4T45-E .
    • Check 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.
       - Check for possible plugged three-way catalytic converter. Refer to Restricted Exhaust in Engine Exhaust.
    • Check the vacuum lines for kinks or leaks.
    • Check the generator output voltage. Refer to Diagnostic System Check - Engine Electrical in Engine Electrical.
    • 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.
       - Check scan tool data. Refer to Scan Tool Data List .