GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Catera 🢒 Engine 🢒 Engine Controls - 3.0L (L81) 🢒 Cuts Out, Misses

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DEFINITION: A steady pulsation or jerking that follows engine speed, which is usually more pronounced as the engine load increases. This condition is not normally felt above 1500 RPM or 48 km/h (30 mph). The exhaust has a steady spitting sound at idle or at low speed.

Preliminary
    • Refer to Important Preliminary Inspections Before Starting in Symptoms .
    • Search for bulletins.
    • Inspect the ECM grounds for being clean, tight, and in the proper locations. Refer to Engine Controls Schematics .
    • Inspect the intake AIR ducts for leaks and proper location.
    • Remove the air filter element and inspect for dirt or for being restricted. Refer to Air Filter Element and Air Cleaner Assembly . Replace if necessary.

Fuel System
    • Test the fuel injectors. Refer to Fuel Injector Solenoid Coil Test .
    • Test for proper fuel pressure. Refer to Fuel System Diagnosis .
    • Test for a restricted fuel filter. Refer to Fuel System Diagnosis .
    • Inspect for a contaminated fuel condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Inspect the items which can cause an engine to run rich (long term fuel trim near -13 percent). For a rich condition, refer to DTC P0172 Fuel Trim System Rich Bank 1 and DTC P0175 Fuel Trim System Rich Bank 2 .
    • Inspect items that can cause an engine to run lean (long term fuel trim near 23 percent). For a lean condition, refer to DTC P0171 Fuel Trim System Lean Bank 1 and DTC P0174 Fuel Trim System Lean Bank 2 .

Sensor/System
    • Use a scan tool in order to monitor the knock sensor (KS) system for excessive spark retard activity. Refer to Detonation/Spark Knock .
    •  Inspect the CKP sensor for proper operation or intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Ignition System
    • Test for proper ignition voltage output with a J 26792 spark tester. Refer to Ignition System Check .
    • Test for secondary ignition system leakage. Perform the procedure in the Diagnostic Aids portion of the Ignition System Check .
    • Remove the spark plugs and inspect for the following conditions:
       - Correct heat range
       - Wet plugs
       - Cracks
       - Wear
       - Improper gap
       - Burned electrodes
       - Heavy deposits
    • An improper spark plug gap may cause a driveability concern. Gap the spark plugs using a wire gauge gap tool. Refer to Spark Plug Replacement in Engine Electrical.
    • Determine the cause of the fouling before replacing the spark plugs if the spark plugs are gas, coolant or oil fouled. Refer to Spark Plug Visual Diagnosis in Engine Electrical.
       - For diagnosis of the rich condition, refer to DTC P0172 Fuel Trim System Rich Bank 1 or DTC P0175 Fuel Trim System Rich Bank 2 .
       - For diagnosis of coolant contaminated spark plugs, refer to Loss of Coolant in Engine Cooling.
       - For diagnosis of oil fouled spark plugs, refer to Oil Consumption Diagnosis in Engine Mechanical.

Engine Mechanical
    • Inspect engine mechanical for the following:
       - Test compression
       - Sticking or leaking valves
       - Worn camshaft lobes
       - Camshaft timing
       - Broken valve springs
       - Excessive oil in combustion chamber-Leaking valve seals
    • For more information, refer to one or more of the following procedures in Engine Mechanical:
       -  Engine Compression Test
       -  Oil Consumption Diagnosis
    • For incorrect basic engine parts, inspect the following components:
       - Camshafts
       - Cylinder heads
       - Pistons, etc.
    •  Refer to Engine Mechanical for diagnosis procedures.

Additional Checks
    • Inspect the following exhaust system components for possible restrictions:
       - The exhaust system for physical damage
       - The mufflers for heat distress or possible internal failure
       - The catalytic converters for possible plugged pipes by comparing the exhaust system back pressure on each side of engine. Refer to Restricted Exhaust System Check .
    • Electromagnetic interference (EMI) on the reference circuit can cause an engine miss condition. A sudden increase in RPM with little change in actual engine RPM change indicates that EMI may be present. Inspect for high voltage components near the ignition control circuits if a condition exists.
    • Inspect the intake manifold and the exhaust manifold passages for casting flash. Refer to Intake Manifold Replacement or Exhaust Manifold Cleaning and Inspection in Engine Mechanical.