GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2001 🢒 Intrigue 🢒 Engine 🢒 Engine Controls - 3.5L 🢒 Lack of Power, Sluggishness, or Sponginess

Lack of Power, Sluggish or Spongy

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 , Important Preliminary Checks Before Starting.
    • Search for bulletins.
    • Verify that the powertrain control module (PCM) grounds are clean, tight, and in the correct locations.
    • Remove and inspect the air filter element for dirt and for restrictions. Replace the element as necessary.

Fuel System Checks
    • Inspect for a low fuel pressure. Refer to Cuts Out, Misses .
    • Inspect for a restricted fuel filter.
    • Inspect for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Inspect the items that can cause an engine to run rich.
    • Inspect the items that can cause an engine to run lean.

Sensor and System Checks
    • Using a scan tool, monitor the knock sensor (KS) system for excessive spark retard activity.
    • Inspect the exhaust gas recirculation (EGR) system for correct operation.

Ignition System

Remove spark plugs. Inspect for the following:

    • Any wet plugs
    • Any cracks
    • Any wear
    • An improper gap
    • Any burned electrodes
    • Any heavy deposits

An improper spark plug gap will cause a driveability problem. The spark plug gapping should be done with a wire gauge gap tool. If the spark plugs are gas or oil fouled, determine the cause of the fouling before replacing the spark plugs.

    • Inspect for a loose ignition control module (ICM) ground.
    • Inspect the spark plugs for the correct heat range.
    • Inspect for the correct ignition voltage output. Refer to Electronic Ignition (EI) System Diagnosis .

Engine Mechanical

Inspect for the following conditions:

    • Any excessive oil in the combustion chambers may indicate leaking valve seals. Refer to Oil Consumption Diagnosis in Engine Mechanical.
    • A low cylinder compression. Refer to Engine Compression Test in Engine Mechanical.
    • Any incorrect basic engine parts. Inspect the following:
       - The camshaft
       - The cylinder heads
       - The pistons, etc.

Refer to Symptoms - Engine Mechanical in Engine Mechanical-3.5L.

Additional Checks
    • Inspect the exhaust system for restrictions. Refer to Restricted Exhaust in Engine Exhaust.
    • Inspect the torque converter clutch (TCC) for correct operation. Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transaxle.
    • Inspect the brake switch assembly of the traction control system . A loss of performance can result from an incorrectly adjusted or a failed extended travel brake switch. The PCM operates in the Torque Management mode when the PCM determines that the brake pedal and the throttle are depressed at the same time.