GM Service Manual Online
For 1990-2009 cars only

Inspection/Test

Action

DEFINITION: Momentary lack of response as the accelerator is pushed down. Can occur at any vehicle speed. Usually more pronounced when first trying to make the vehicle move, as from a stop sign. May cause the engine to stall if severe enough.

Sensor/System

    • Inspect the mass air flow (MAF) sensor for proper installation, obstruction, contamination, and damage. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .
    • Inspect the MAF sensor for proper seating of the connector and terminal.
    • Test the manifold absolute pressure (MAP) sensor for proper installation, obstruction, and damage. Refer to Manifold Absolute Pressure Sensor Replacement .
    • Ensure the quality of the MAP sensor vacuum source.

Fuel System

    •  Test the fuel system for correct operation, restriction, volume, and pressure. Refer to Fuel System Diagnosis .
    • Test for proper operation of the fuel injectors. Refer to Fuel Injector Diagnosis .
    • Test for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Inspect the throttle body for coking. Refer to Throttle Body Inspection and Cleaning .
    • Inspect for lean or rich conditions. Refer to DTC P0171, P0172, P0174 or P0175 Conditions for Running the DTC. Refer to DTC P0171 or P0172 or DTC P0174 or P0175 .

Ignition System

    • Inspect for proper ignition system operation. Refer to Electronic Ignition (EI) System Diagnosis .
    • Inspect the spark plugs. Refer to Spark Plug Inspection .
    • Inspect the spark plugs for correct application. Refer to Ignition System Specifications .
    • Inspect for damaged ignition coils within the ignition coil module assemblies.
    • Inspect for damaged or misaligned spark plug boots.

Additional Inspections

    • Inspect the engine mechanical for oil consumption, correct engine compression, and correct base engine timing. Refer to Symptoms - Engine Mechanical .
    • Inspect the engine electrical system for correct operation. Refer to Symptoms - Engine Electrical .
    • Inspect the engine cooling system. Refer to Symptoms - Engine Cooling .
    • Inspect the engine exhaust. Refer to Symptoms - Engine Exhaust .
    • Inspect engine mounts. Refer to Engine Mount Inspection .
    • Inspect the heating ventilation air conditioning (HVAC) system operation. Refer to Symptoms - HVAC Systems - Automatic and Air Conditioning (A/C) System Performance Test .
    • Inspect the transmission for proper shifting and torque convertor clutch (TCC) engagement. Refer to Symptoms - Automatic Transmission .