GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2002 🢒 Bonneville 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Cuts Out, Misses

Checks

Action

DEFINITION: Steady pulsation or jerking that follows engine speed, usually more noticeable as engine load increases.

Preliminary
    • Refer to Important Preliminary Checks Before Starting in Symptoms - Engine Controls .
    • Refer to visual checks and physical checks in Symptoms - Engine Controls .
    • Search for bulletins.

Fuel System
    • Check the fuel system pressure. Refer to Fuel System Diagnosis .
    • Check the fuel injectors. Refer to Fuel Injector Solenoid Coil Test .
    • Check for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Inspect for conditions that can cause a rich fuel mixture. Refer to Diagnostic Aids for DTC P0172 .
    • Inspect for conditions that can cause a lean fuel mixture. Refer to Diagnostic Aids for DTC P0171 .
    • Check for fuel in the vacuum hose of the fuel pressure regulator. If fuel is present, replace the fuel pressure regulator. Refer to Fuel Pressure Regulator Replacement .

Sensor/System
    • Check for conditions which cause an incorrect idle speed.
       - Check for deposits or for damage to the throttle body.
       - Check for a restricted air intake duct or for a dirty air cleaner element, refer to Air Cleaner Element Replacement .
       - Check for a large vacuum leak.
    • Check the throttle position (TP) sensor and the related wiring. Refer to DTC P0123 .
    • Check the exhaust gas recirculation (EGR) system:
       - Inspect the EGR pipes and the adapter for vacuum leaks.
       - Remove the EGR valve, and check for a sticking pintle. Refer to Exhaust Gas Recirculation Valve Replacement .
    • Check the positive crankcase ventilation (PCV) valve for proper installation. Refer to Crankcase Ventilation System Inspection/Diagnosis in Engine Mechanical.
    • Verify the correct operation of the park neutral position (PNP) switch. Compare the transaxle range switch input with the vehicle in drive and with the gear selector in drive or in overdrive.
    • Check for the following conditions:
       - Check for bent harmonic balancer interrupter rings.
       - Check for a damaged crankshaft position (CKP) sensor.

Ignition System
    • Check for the correct ignition voltage output using the following steps:
       - Attach the J 26792 Spark Tester to the 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 tested coil.
       - Connect another spark plug wire between the remaining tower of the coil that is being tested and the ground.
       - Crank the engine, and observe the spark tester. A bright blue spark should be observed.
       - Repeat the above steps for each coil.
    • If adequate spark is not present at the coils, check for the following conditions:
       - Inspect the coils for cracks, for carbon tracking and/or arcing, or for a resistance value outside the specified range.

Secondary Coil Resistance
5,000-8,000 ohms

   Important:: If carbon tracking is detected on any component, replace that component and the component's respective match.

       - Inspect the spark plug wires for the following conditions: cracks, any arcing, incorrect firing, incorrect routing, carbon tracking, plug boot damage, pinched wires, or a resistance value more than the specified value.

Spark Plug Wire Resistance
3280-4921 ohms per meter (1,000-1,500 ohms per foot)

   Important: Spraying the secondary ignition wires with a small amount of water may help locate an intermittent condition. Ignition components will arc to ground if a secondary component is malfunctioning.

       - Check the ignition control module for a malfunction.
       - Check the ignition system wiring for a loose ignition module feed, a bad ground connection, or for a damaged wiring system .
    • Remove the spark plugs.
    • Inspect the spark plugs for the following conditions:
       - Fouling
       - Cracks

   Important:: If carbon tracking is detected on any component, replace that component and the component's respective match.

       - Check the spark plugs for signs of carbon tracking on the porcelain or for any arcing at the plug wire contact.
       - Check the spark plugs for an incorrect gap. Refer to Maintenance Items in Maintenance and Lubrication.
       - Check the spark plugs for damaged electrodes.
       - Check the spark plugs for an incorrect heat range. Refer to Maintenance Items in Maintenance and Lubrication.
    • If the spark plugs are fouled from gas or from oil , the cause of the fouling must be determined before replacing the spark plugs.
    • Check for the following ignition system conditions:
       - Check for an Intermittent CKP Sync or CKP 18X signal.
       - Check for an intermittent sensor ground circuit or for an ignition positive voltage circuit to the crankshaft (CKP) or to the camshaft position (CMP) sensor.
       - Check for a intermittent 3X reference signal.
       - Check for a intermittent camshaft position signal.

Engine Mechanical
    • Check in Engine Mechanical for the following conditions:
       - Check the compression. Refer to Engine Compression Test in Engine Mechanical.
       - Check for sticking or for leaking valves. Refer to Cylinder Leakage Test in Engine Mechanical.
       - Check for worn camshaft lobes.
       - Check the valve timing.
       - Check for bent push rods.
       - Check for worn rocker arms.
       - Check for broken valve springs.
       - Check for excess oil in the combustion chamber and for leaking valve seals.
    • Inspect for incorrect engine parts, such as the following basic components:
       - The camshaft
       - The cylinder heads
       - The pistons
    • Refer to Symptoms - Engine Mechanical in Engine Mechanical

Additional Checks
    • Check the exhaust system for a restriction. Refer to Restricted Exhaust .
       - Inspect the exhaust system for damaged pipes or for collapsed pipes.
       - Inspect the muffler for heat damage or for an internal condition.
       - Check for a plugged three-way catalytic converter. Refer to Restricted Exhaust .
    • Electromagnetic interference (EMI) can cause an engine miss condition on the reference circuit. EMI can usually be detected by monitoring the engine RPM with a scan tool. A sudden increase or a sudden decrease in RPM with little change in actual engine RPM indicates that EMI is present. Check the routing of the secondary ignition wires. Check the ignition coils for cracks, carbon tracking, or for signs of arcing.
    • Check the intake and the exhaust manifold passages for casting flash. Refer to Upper Intake Manifold Replacement and Lower Intake Manifold Replacement in Engine Mechanical.
    • Check for loose, worn, or broken motor mounts. Refer to Engine Mount Inspection in Engine Mechanical.