Mercury MerCruiser MCM 454 Mag MPI Service Manual page 587

FUEL INJECTION SYSTEM TROUBLESHOOTING
Poor Fuel Economy Symptom (Continued)
8
9
10
11
12
Index
Page 5D-28
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1. Visual (physically) check vacuum
hoses for splits, kinks and improper
connections and routing.
2. If a problem is found, repair as nec-
essary.
Was a repair required?
1. Check engine compression for
being low.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check exhaust system for possible
restriction.
2. Inspect exhaust system for dam-
aged or collapsed pipes.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check for excessive resistance on
the bottom of the boat such as dirt,
barnacles, etc.
2. Check for proper propeller size and
pitch for that application.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Review all diagnostic procedures
within this table.
2. When all procedures have been
completed and no malfunctions are
found, review/inspect the following:
Visual/physical inspection.
Scan tool data.
All connections within a suspected
circuit and/or system.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
SERVICE MANUAL NUMBER 23
Go to OBD
System
- Go to Step 9
Check
Go to OBD
System
- Go to Step 10
Check
Go to OBD
System
- Go to Step 11
Check
Go to OBD
System
Go to Step 12
-
Check
MerCruiser
Go to OBD
Customer
System
-
Check
90-861326--1 MARCH 1999
Contact
Service