Checks
| Actions
|
DEFINITION:
Fuel ignites in the intake manifold, or in the exhaust system, making loud
popping noise.
|
Preliminary Checks
|
| • | Search for service bulletins. |
| • | Connect a scan tool and look at the misfire data to possibly isolate
a specific cylinder fault |
|
Fuel
System
|
|
Ignition
System
|
| • | Check for proper ignition voltage output with the spark tester J 26792
. |
| • | Check the spark plugs for the following conditions: |
| - | Cracks on the spark plugs |
| - | Improper spark plug gap |
| - | Burned electrodes or heavy deposits |
| • | If the spark plugs are fuel or oil fouled, the cause of the fouling
must be determined before replacing the spark plugs. |
| • | Check the ignition control module (ICM) for proper ground connection. |
| • | Check the ignition coils for cracks or carbon tracking. |
| • | Check the spark plug wires for proper resistance and condition. |
|
Engine
Mechanical
|
| • | Check the following conditions in engine mechanical: |
| - | Sticking or leaking valves |
| - | Excessive oil in combustion chamber and leaking valve seals |
| - | Low cylinder compression |
| • | Inspect the following incorrect basic engine parts: |
| • | Refer to the appropriate diagnostic procedures in Engine Mechanical. |
|
Additional
Checks
|
| • | Check the exhaust manifold for cracks or gasket leaks. Refer to
the appropriate diagnostic procedures in Engine Mechanical. |
| • | Check the following conditions for a possible exhaust leak: |
| - | Damaged or collapsed pipes |
| - | Heat distress or possible internal failure of mufflers |
| - | Crank signal intermittent condition |
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