For 1990-2009 cars

#### Cuts Out, Misses

Checks | Action
--- | ---
DEFINITION: A steady pulsation or jerking that increases with the engine speed. The condition is usually more pronounced when the engine load increases.
Preliminary |

• | Refer to Diagnostic System Check - Engine Controls .

• | Refer to Symptoms - Engine Controls .

• | Search the service bulletins.

Fuel System | Check for the following conditions:

• | The system fuel pressure--Refer to Fuel System Diagnosis .

• | The fuel injectors--Refer to Fuel Injector Solenoid Coil Test .

• | Contaminated fuel--Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

• | Check for a restricted fuel filter.

• | Conditions which can cause an engine to run rich, indicating that the long term fuel trim is significantly in the negative range--Refer to Diagnostic Aids for DTC P0172 .

• | Conditions which can cause an engine to run lean, indicating that the long term fuel trim is significantly in the positive range--Refer to Diagnostic Aids for DTC P0171 .

• | Proper operation of the evaporative emission (EVAP) control system. Refer to Evaporative Emission Control System Description .

• | Check for fuel in the fuel pressure regulator vacuum hose.

Sensor/System | Check for the following conditions:

• | The oxygen sensor (O2S 1)--The O2S 1 should quickly respond to the different throttle positions. If the sensor does not respond, check the O2S 1 for silicon, or for other contaminants from the fuel, or from the use of an improper RTV sealant. The sensor may have a white powdery coating. Silicon contamination causes a high but false O2S 1 signal voltage, indicating a rich exhaust indication. The powertrain control module (PCM) will reduce the amount of fuel that is delivered to the engine, causing a severe driveability problem.

• | Proper operation of the following components:

- | The manifold absolute pressure (MAP) sensor. Refer to DTC P0105 .

- | The throttle position (TP) sensor. Refer to DTC P0105 .

- | The engine coolant temperature (ECT) sensor. Refer to DTC P0117 and DTC P0118 .

Ignition System | Check for the following conditions:

• | Proper ignition voltage output--Use the J 36012-A Ignition System Diagnostic Harness and the J 26792 Spark Tester, or equivalent.

• | Check the spark plugs for the following conditions:

- | Wet spark plugs

- | Fuel-fouled spark plugs

- | Cracked spark plugs

- | Wear

- | Improper spark plug gap

- | Burned electrodes

- | Heavy deposits

• | If the spark plugs are fuel or oil-fouled, determine the cause of the fouling before you replace the spark plugs.

• | The ignition control module (ICM) for proper ground connection

• | The ignition coils for cracks or carbon tracking

• | The internal and external ignition coil housing for cracks and for carbon tracking

Engine Mechanical | Check for the following conditions:

• | Sticking valves

• | Leaking valves

• | Worn camshaft lobes

• | The valve timing

• | Broken valve springs

• | Excessive oil in the combustion chamber, caused by leaking valve seals

• | Proper oil viscosity

• | Low cylinder compression

• | Incorrect basic engine parts--Inspect the following components:

- | The camshafts

- | The cylinder head

- | The pistons

Refer to Symptoms - Engine Mechanical in Engine Mechanical 2.2 L (L61).

Additional Checks |

• | Check the exhaust system for possible restrictions. Check for the following conditions:

- | Inspect the exhaust system for damaged pipes, or for collapsed pipes.

- | Inspect the mufflers for heat distress, or for possible internal failure.

- | Inspect for a plugged 3-way catalytic converter. Refer to Restricted Exhaust in Engine Exhaust.

• | Electromagnetic interference (EMI) on the reference circuit can cause an engine miss condition. You can usually detect EMI by monitoring the engine RPM with a scan tool. A sudden increase in the RPM, with little change in the actual engine RPM change indicates that EMI is present. If a problem exists, check the routing for the following components:

- | The secondary ignition wires

- | The high-voltage components, near the ignition control circuits

• | Check for malfunctioning engine mounts. Refer to Symptoms - Engine Mechanical in Engine Mechanical 2.2 L (L61).

• | The following conditions can cause an intermittent connection:

- | Poor electrical connections

- | Rubbed through wire insulation

- | Broken wire inside the insulation

• | Thoroughly check any circuitry that you suspect of causing an intermittent complaint for the following conditions:

- | Backed-out terminals

- | Improper terminal mating

- | Improperly-formed terminals

- | Damaged terminals

- | Poor terminal-to-wire electrical connections

- | A damaged wiring harness

- | Corrosion