GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Catera 🢒 Engine 🢒 Engine Controls - 3.0L (L81) 🢒 Cuts Out, Misses

Checks

Action

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 - Engine Controls .
    • Search for bulletins.
    • Inspect the engine control module (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 Cleaner Element Replacement .

Fuel System
    • Inspect the fuel system. Refer to Fuel System Diagnosis .
    • Test for incorrect fuel pressure.
    • Test for a restricted fuel filter.
    • Test 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 or P0175 .
    • 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 or P0174 .

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 intermittant 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 Electronic Ignition (EI) System Diagnosis .
    • Test for secondary ignition system leakage. Perform the procedure in the Diagnostic Aids portion of the Electronic Ignition (EI) System Diagnosis .
    • 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 .
    • 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 Inspection . Once you determine the cause of the fouling, refer to one of the following procedures:
       - For diagnosis of the rich condition, refer to DTC P0172 or P0175 .
       - 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-3.0L (L81).

Engine Mechanical
    • Inspect engine mechanical for the following conditions:
       - 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-3.0L (L81):
       -  Engine Compression Test
       -  Oil Consumption Diagnosis
    • Inspect the following components for incorrect basic engine parts:
       - Camshafts
       - Cylinder heads
       - Pistons, etc.
    •  Refer to Engine Mechanical-3.0L (L81) 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 the engine. Refer to Restricted Exhaust in Engine Exhaust.
    • 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 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 one of the following procedures in Engine Mechanical-3.0L (L81):
      •  Intake Manifold Replacement