Cuts Out, Misses Symptom
Checks
| Action
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DEFINITION: A steady pulsation or jerking that follows engine speed,
usually more pronounced as the engine load increases. The exhaust has a steady
spitting sound at idle, low speed, or on hard acceleration.
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Preliminary Checks
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| • | Refer to
Symptoms
for the
Important Preliminary Checks. |
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Ignition System Checks
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| • | Check for a cylinder misfire: |
| | Notice: Do not perform this test for more than 2 minutes in order to
prevent damaging the catalytic converter.
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| - | Allow the engine to stabilize then disconnect the Idle Air Control (IAC)
motor. |
| - | Remove one spark plug wire at a time, using insulated pliers. |
| - | Reconnect the IAC motor with the ignition OFF. |
| - | Check for spark on the suspected cylinders with the J 26792
spark tester, or equivalent, if there is no
RPM drop on one or more cylinders, or excessive variation in drop. |
| - | Remove the spark plugs in these cylinders and check for the following
if there is spark: |
| • | Check the spark plug wire resistance. The resistance should not
exceed 30,000 ohms. |
| • | Check the distributor rotor and the distributor cap. |
| • | If the previous checks did not find the problem, visually check
the following: |
| - | The ignition system for moisture, dust, cracks, burns, etc. |
| - | With the engine running, spray the plug wires with a fine water
mist to check for shorts. |
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Engine Mechanical Checks
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| • | Check the engine for the following: |
| - | Broken or weak valve springs |
| - | Refer to Engine Mechanical. |
| • | Check the intake and exhaust manifold passage for casting flash.
Refer to Engine Mechanical. |
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Fuel System Checks
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| • | Check the fuel system for a plugged fuel filter, low fuel pressure,
etc. Refer to
Fuel System Diagnosis
. |
| • | Check for water contamination in the fuel. |
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