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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Ignition System Checks
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Important: Do not perform this test for more than 2 minutes in order to prevent
damage to the catalytic converter.
Check for ignition misfire.
- Start the engine.
- Disconnect the fuel injectors one at the time.
- An equal RPM drop on all cylinders (within 50 RPM) indicates
a common condition that is affecting all cylinders.
- Check for spark on the suspected cylinders with a J 26792
spark tester, or equivalent, if there
is no RPM drop on one or more cylinders.
- If there is no spark, refer to
Engine Cranks but Does Not Run
.
- Check for the proper secondary voltage output with a J 26792
spark tester, or an equivalent. Refer
to
Electronic Ignition (EI) System Diagnosis
.
- Inspect the spark plugs for correct operation and performance.
Refer to
Spark Plug Inspection
.
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Engine Mechanical Checks
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• | Check for any of the following engine mechanical problems: |
- | Faulty hydraulic lifter assemblies |
- | Broken or weak valve springs |
- | Incorrect or worn camshaft |
• | Check the intake and exhaust manifold passages for casting flash. |
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Fuel System Checks
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• | Check for a restricted fuel filter or incorrect fuel pressure. |
• | Check for water contamination of the fuel. |
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