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For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Intrigue 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 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 Important Preliminary Checks.
    • Refer to Visual/Physical Checks.
    • Search for bulletins.

Fuel System Checks
    • Test the system fuel pressure. Refer to Fuel System Pressure Test .
    • Test for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Test the items which can cause an engine to run rich. Refer to DTC P0172 Fuel Trim System Rich .
    • Test the items that can cause an engine to run lean. Refer to DTC P0171 Fuel Trim System Lean .

Sensor/System
    • Using a scan tool, test for excessive spark retard activity. Refer to Knock Sensor (KS) System Description .
    • Test the EGR system for proper operation. Refer to Exhaust Gas Recirculation (EGR) System Description .
    • Test for a restricted air intake system. Refer to Air Intake System Description .

Ignition System
    • Test for proper ignition voltage output using the following steps:
       - Clip the J 26792 spark tester to engine ground.
       - Connect one end of a spark plug wire to the spark tester. Leave the other end of the spark plug wire connected to the coil being tested.
       - Connect one end of another spark plug wire to the other coil tower. Connect the other end of the spark plug wire to ground.
       - Crank the engine while observing the spark tester. Spark should be observed.
       - Repeat the above steps for each coil.
    • If adequate spark is not present at the coils, inspect or test for the following conditions:
       - Inspect the coils for cracks, carbon tracking/arcing, or a resistance value outside the 5000 - 8000 ohms range.
       - Inspect the spark plug wires for signs of arcing/cross firing, cracks, carbon tracking, plug boot damage, pinched wires , improper routing, or a resistance value other than 600 ohms per ft. (1968 ohms per meter).

   Important: Spraying the secondary ignition wires with a light mist of water may help locate an intermittent problem. Ignition components arc to ground when a secondary component is faulty.

       - Test for a defective module.
       - Inspect the ignition system wiring for a loose ignition module feed or ground connection, or damaged system wiring.
    • Remove the spark plugs and inspect for the following:
       - Fouled plugs
       - Cracks
       - Wear
       - Improper gap
       - Burned or damaged electrodes
       - Improper heat range or reach
    • If the spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.

Engine Mechanical
    • Test for excessive oil in the combustion chamber or leaking valve seals. Refer to Cylinder Leakage Test .
    • Test for low cylinder compression. Refer to Engine Compression Test
    • Inspect for incorrect basic engine parts. Inspect the following:
       - The camshaft
       - The cylinder heads
       - The pistons, etc.

Additional Checks

Check exhaust system for possible restrictions. Check for the following:

    • Inspect the exhaust system for damaged or collapsed pipes.
    • Inspect the mufflers for heat distress or possible internal failure.
    • Test for a plugged 3-way catalytic converter. Refer to Restricted Exhaust System Check and Exhaust System Inspection in Engine Exhaust.
    • Test for proper TCC operation.