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For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1999 🢒 S/T Isuzu - 2WD 🢒 Engine 🢒 Engine Controls - 2.2L 🢒 Cuts Out, Misses

Cuts Out, Misses

Checks

Action

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

Preliminary
    •  Refer to Symptoms .
    •  Search for service bulletins.

Fuel System
    • Check system fuel pressure. Refer to Fuel System Diagnosis .
    • Check the fuel injectors. Refer to Fuel Injector Balance Test .
    • Check for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis Testing.
    • Check the fuel filter for being plugged or restricted.
    • Check items which can cause an engine to run rich (long term fuel trim significantly in the negative range). Refer to Diagnostic Aids for DTC P0172 Fuel Trim System Rich .
    • Check items that can cause an engine to run lean (long term fuel trim significantly in the positive range). Refer to Diagnostic Aids for DTC P0171 Fuel Trim System Lean .
    • Check for proper operation of the Evaporative Emission (EVAP) control system.
    • Check for fuel in the Fuel Pressure Regulator vacuum hose.

Sensor/System
    • Check the Oxygen sensor (O2S 1). The O2S 1 should respond quickly to different throttle positions. If not, check the O2S 1 for silicon or other contaminants from fuel or the use of improper RTV sealant. The sensors may have a white powdery coating. Silicon contamination causes a high but false O2S 1 signal voltage (rich exhaust indication). The PCM will reduce the amount of fuel delivered to the engine, causing a severe driveability problem. Refer to Oxygen sensor in Information Sensors/Switches Description .
    • Check for proper operation of the MAP Sensor.
    • Check for proper operation of the TP sensor.
    • Check for proper operation of the ECT sensor.

Ignition System
    • Check for proper ignition voltage output with the J 26792 spark tester or equivalent.
    • Check the spark plugs for the following conditions:
       - Check for wet or fuel fouled spark plugs.
       - Check for cracks on the spark plugs.
       - Check for wear.
       - Check for improper spark plug gap.
       - Check for burned electrodes or heavy deposits.
    • If the spark plugs are fuel or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.
    • Check the Ignition Control Module (ICM) for proper ground connection.
    • Check the ignition coils for cracks or carbon tracking.
    • Check the spark plug wires for proper resistance and condition.

Engine Mechanical
    • Check engine mechanical for the following:
       - Check compression.
       - Sticking or leaking valves.
       - Worn camshaft lobe(s).
       - Valve timing.
       - Bent push rods.
       - Worn rocker arms.
       - Broken valve springs.
       - Excessive oil in combustion chamber-Leaking valve seals.
       - Low cylinder compression.
    • For incorrect basic engine parts. Inspect the following:
       - Camshaft
       - Cylinder heads
       - Pistons, etc.
    • Refer to Base Engine Misfire Diagnosis in Engine Mechanical for diagnosis procedures.

Additional Checks
    • Check exhaust system for possible restrictions. Check for the following:
       - Inspect exhaust system for damaged or collapsed pipes.
       - Inspect mufflers for heat distress or possible internal failure.
       - For possible plugged Three-Way catalytic converter. Refer to Restricted Exhaust System Check and Exhaust System.
    •  An engine miss condition can be caused by Electromagnetic Interference (EMI) on the reference circuit. EMI can usually be detected by monitoring engine RPM with a scan tool. A sudden increase in RPM with little change in actual engine RPM change, indicates EMI is present. If a problem exists, check routing of secondary ignition wires, high voltage components (Near Ignition Control circuits).
    • Check for intake and exhaust manifold passages for casting flash.
    • Check for malfunctioning motor mounts. Refer to Engine Mount Inspection in Engine Mechanical.