GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 Engine 🢒 Engine Controls - 5.7L 🢒 Surges/Chuggles

Checks

Action

DEFINITION: The engine power varies during steady throttle or during cruise. The vehicle speed appears to increase or to decrease with no change in the accelerator pedal position.

Preliminary
    • Refer to Important Preliminary Checks Before Starting in Symptoms - Engine Controls .
    • Search for bulletins.
    • Inspect the powertrain control module (PCM) grounds. Ensure that they are clean, tight, and in the proper locations. Refer to Engine Controls Schematics .
    • Ensure that the driver understands the operation of the Transmission Torque Converter Clutch (TCC) and A/C compressor operation as explained in the owners manual. Inform the customer how the TCC and the A/C clutch operates.

Sensor/System
    • Monitor the heated oxygen sensors (HO2S) voltages. The HO2S should respond quickly to the different throttle positions. If the sensors do not respond, inspect the HO2S for silicon or for other contaminates from the fuel , or from the use of an improper RTV sealant. The sensors may have a white powdery coating, which can result in a high, but false, signal voltage, indicating a rich exhaust indication. The PCM then reduces the amount of fuel that is delivered to the engine, causing a severe driveability condition.
    • Inspect the mass air flow (MAF) sensor connections. Repair or replace the terminals. Refer to Repairing Connector Terminals in Wiring Systems.

Fuel System
    • Test for incorrect fuel pressure. Refer to Fuel System Diagnosis .
    • Test for a restricted fuel filter. Refer to Fuel System Diagnosis .
    • Test for a contaminated fuel condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Inspect that each injector harness is connected to the correct injector/cylinder according to the firing order. The firing order is 1-8-7-2-6-5-4-3. Relocate the injector harnesses as necessary.
    • Inspect the conditions that cause an engine to run rich, with a long-term fuel trim near -13 percent. For a rich condition, refer to DTC P0132 or P0152 .
    • Inspect for conditions that can cause an engine to run lean, (with a long-term fuel trim near 24 percent. For a lean condition, refer to DTC P0131 or P0151 .

Ignition System
    • Wet the secondary ignition system with water from a spray bottle. Wetting the secondary ignition system may help locate damaged or deteriorated components. When you apply the water, look and listen for arcing and misfiring.
    • Test for proper ignition voltage output with spark tester J 26792 . Refer to Electronic Ignition (EI) System Diagnosis .
    • Remove the spark plugs. Inspect for the following conditions:
       - The correct heat range.
       - Wet plugs
       - Cracks
       - Wear
       - Improper gap
       - Burned electrodes
       - Heavy deposits
       - Refer to Spark Plug Inspection in Engine Electrical.
    • An improper spark plug gap can cause a driveability condition. Gap the spark plugs using a wire gauge gap tool. Refer to Spark Plug Replacement in Engine Electrical.
    • Before you replace the spark plugs, determine the cause of the fouling.
       - Gas fouling--Refer to DTC P0172 or P0175 .
       - Oil fouling--Refer to Oil Consumption Diagnosis in Engine Mechanical-5.7L.
       - Coolant fouling--Refer to Loss of Coolant in Engine Cooling.
    • Inspect for loose ignition coil grounds. Refer to Electronic Ignition (EI) System Diagnosis .

Engine Mechanical

Ensure that the engine coolant temperature is not above 132°C (270°F). This condition causes the PCM to operate in Engine Coolant Over Temperature-Fuel Disabled Mode. During Engine Coolant Over temperature-Fuel Disabled Mode, the PCM turns the fuel OFF to 4 cylinders at a time, in order to keep the engine temperatures from reaching damaging levels. The customer perceives the Engine Coolant Over Temperature-Fuel Disabled Mode as a lack of power, a miss, or a rough idle. If the engine operates in the Engine Coolant Over Temperature-Fuel Disabled Mode, refer to Engine Overheating in Engine Cooling.

Additional Checks
    • Inspect the vacuum hoses for splits, for kinks, and for proper connections and routing as shown on the Vehicle Emission Control Information label. Refer to Emission Hose Routing Diagram .
    • Test the Transmission Torque Converter Clutch (TCC) operation. A TCC applying too soon can cause the engine to spark knock. Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transmission-4L60-E.