FUEL INJECTION SYSTEM TROUBLESHOOTING
SERVICE MANUAL NUMBER 23
Page 5D-16
90-861326--1 MARCH 1999
Lack of Power, Sluggish or Spongy Symptom (Continued)
18
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
necessary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 19
19
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?
-
Go to OBD
System
Check
Contact
MerCruiser
Customer
Service
Detonation/Spark Knock Symptom
Step
Action
Value(s)
Yes
No
Definition: A mild to severe ping, usually worse under acceleration. The engine makes
sharp metallic knocks that change with throttle opening.
1
Was the “On-Board Diagnostic” (OBD)
System Check performed?
-
Go to Step 2
Go to OBD
System Check
2
Was visual/physical check performed?
-
Go to Step 3
Go to Visual/
Physical
Check
3
1. Check base timing.
•
Refer to Ignition Timing Set Proce-
dure in the
Distributor Ignition sec-
tion.
2. If a problem is found, repair as
necessary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 4
4
1. Check for proper operation of
Ignition Control (IC) circuit and the
Knock Sensor (KS) circuit.
2. If a problem is found, repair as
necessary.
Was a problem found?
-
Go to OBD
System
Check
Go to Step 5
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