PleasureCraft Engine Group 5.0L, Diagnostic Manual

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7 - 22 Symptoms 5.0/5.7/6.0/8.1L
MEFI 4 - PCM
Backfi re Symptom
Step Action Value Yes No
Defi nition: Fuel ignites in the intake manifold, or in the exhaust system, making loud popping noise.
1
Was the “On-Board Diagnostic (OBD) System Check” Go to OBD
performed? — Go to Step 2 System Check
2
Was visual/physical check performed? Go to Visual/
— Go to Step 3 Physical check
1. Check fl ame arrestor for proper installation per
3
manufactures recommendation.
2. If a problem is found, repair as necessary. Go to OBD
Was a problem found? — System Check Go to Step 4
1. Check for proper fuel pressure.
4
•
Refer to Table A-4.
2. If a problem is found, repair as necessary. Go to OBD
Was a problem found? — System Check Go to Step 5
1. Check for correct Cam Retard (5.0/5.7L only).
•
Refer to “Setting Cam Retard Procedure” in the
5
Distributor Ignition section.
2. If a problem is found, repair as necessary. Go to OBD
Was a problem found? 43-47 degrees System Check Go to Step 6
1. Check to see if engine is going into RPM reduction.
6
2. If a problem is found, repair as necessary. Go to OBD
Was a problem found? — System Check Go to Step 7
Check the injector connections. If any of the injectors are
7
connected to an incorrect cylinder, correct as necessary. Go to OBD
Was a problem found? — System Check Go to Step 8
1. Check fuel injectors.
•
Refer to Injector Coil Test and Injector Balance
8
Test at the end of this section.
2. If a problem is found, repair as necessary. Go to OBD
Was a problem found? — System Check Go to Step 9
1. Check for proper operation of Ignition Control (IC)
9
circuit and the Knock Sensor (KS) circuit(s).
2. If a problem is found, repair as necessary. Go to OBD
Was a problem found? — System Check Go to Step 10
1. Check integrity of the primary and secondary wiring.
2. Check routing of the wiring.
10
3. Check condition of IC module, pick-up coil, distributor
cap, rotor and spark plug wires.
4. If a problem is found, repair as necessary. Go to OBD
Was a problem found? — System Check Go to Step 11
1. Check ignition coil for cracks or carbon tracking.
11
2. If a problem is found, repair as necessary. Go to OBD
Was a problem found? — System Check Go to Step 12