Cuts Out, Misses Symptom - Mercury MerCruiser MCM 454 Mag MPI Service Manual

SERVICE MANUAL NUMBER 23
Hesitation, Sag, Stumble Symptom (Continued)

Cuts Out, Misses Symptom

Step
Definition: Steady pulsation or jerking that follows engine speed, usually more
pronounced as engine load increases. The exhaust has a steady spitting sound at idle,
low speed or on hard acceleration for fuel starvation that can cause engine to cut out.
Index
90-861326--1 MARCH 1999
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1. Review all diagnostic procedures
within this table.
2. If all procedures have been com-
pleted and no malfunctions have
been found, review/inspect the fol-
lowing:
Visual/physical inspection.
14
Scan tool data.
All electrical connections within a
suspected circuit and/or system.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
Action
Was the "On-Board Diagnostic" (OBD)
1
System Check performed?
Was visual/physical check performed?
2
1. Check for contaminated fuel.
2. Check water separating fuel filter.
3
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check for proper fuel pressure while
the condition exists.
Refer to Table A-4 in "General Sys-
4 tem Diagnostics" section.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Disconnect all injector harness con-
nectors and install an injector test
light J 34730-2 between the harness
terminal connector of each injector.
2. Crank engine and note light on each
connector. If test light fails to blink at
5
any one of the connectors, it is a
faulty injector drive circuit harness,
connector or terminal.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
FUEL INJECTION SYSTEM TROUBLESHOOTING
Go to OBD
System
-
Check
Value(s) Yes
- Go to Step 2
- Go to Step 3
Go to OBD
System
-
Check
Go to OBD
System
-
Check
Go to OBD
System
-
Check
Contact
MerCruiser
Customer
Service
No
Go to OBD
System Check
Go to Visual/
Physical
Check
Go to Step 4
Go to Step 5
Go to Step 6
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