GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 S10 Pickup - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Surges/Chuggles

Checks

Action

Definition: The engine has a power variation under a steady throttle or cruise. The vehicle feels as if it speeds up and slows down with no change in the accelerator pedal.

Preliminary Checks
    • Refer to Symptoms .
    • Be sure the driver understands the Torque Converter Clutch operation.
    • Be sure the driver understands the A/C Compressor operation.

Sensor Check

Check the (Heated) Oxygen Sensor (HO2S) performance. Refer to the following DTC tables:

Fuel System Checks
    • Check for a Rich or Lean symptom that causes the condition. Drive the vehicle at the speed of the complaint. Monitoring the Fuel Trim will help identify the problem.
    • Lean - The Long Term Fuel Trim will be greater than 150. Refer to DTC P0132 HO2S Circuit High Voltage Bank 1 Sensor 1 Diagnostic Aids.
    • Rich - The Long Term Fuel Trim will be less than 115. Refer to DTC P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1 Diagnostic Aids.
    • Check the fuel pressure while the condition exists. Refer to Fuel System Diagnosis .
    • Check the in-line fuel filter for a restrictions.

Ignition System Checks
    • Check for the proper ignition output voltage using the spark tester J 26792 or the equivalent. Refer to Enhanced Ignition System Diagnosis .
    • Check the spark plugs. Remove the plugs and inspect them for the following conditions:
       - Wetness
       - Cracks
       - Wear
       - Improper gap
       - Burned electrodes
       - Heavy deposits
    • Check the Crankshaft Position (CKP) sensor. Refer to DTC P0339 Crankshaft Position (CKP) Sensor Circuit Intermittent .

Additional Checks
    • Check the Control Module grounds for being clean, tight, and in their proper locations.
    • Check the generator output voltage.
    • Check the vacuum hoses for kinks or leaks. Refer to the Vehicle Emission Control Information label.
    • Check for an intermittent EGR problem. Refer to Exhaust Gas Recirculation (EGR) System Diagnosis .
    • Check for Torque Converter Clutch (TCC) operation. Refer to Transmissions.