SERVICE MANUAL NUMBER 23
FUEL INJECTION SYSTEM TROUBLESHOOTING
Lack of Power, Sluggish or Spongy Symptom (Continued)
1.
Check for intermittent opens or short
to grounds in the ECT sensor, MAP
sensor and TP sensor circuits. Also
check or throttle linkage sticking,
binding or worn.
12
2.
3.
An intermittent failure may not store
a DTC.
If a problem is found, repair as
necessary.
Go to OBD
System
Check
Was a problem found?
-
Go to Step 13
Go to Step 14
1.
Check ECM grounds for being
clean, tight and in their proper
locations.
13
14
15
2.
If a problem is found, repair as
necessary.
Go to OBD
System
Check
Was a problem found?
-
-
1.
Check for engine going into rpm
reduction mode.
Not
Applicable
to
MerCruiser
EFI or MPI Go to Step 15
2. If a problem is found, repair as
necessary.
Was a problem found?
1.
Check diagnostic test CKT 451 for
being shorted to ground. This will
cause the rpm to be lowered.
If a problem is found, repair as
necessary.
2.
Go to OBD
System
Check
Was a problem found?
-
Go to Step 16
1.
2.
3.
Check or proper alternator voltage
output.
The voltage should be between
specified values.
If a problem is found, repair as
necessary.
16
Go to OBD
System
Check
11-16
Volts
Was a problem found?
Go to Step 17
1.
Check for the following Engine
Mechanical problems:
•
•
•
Low compression.
Leaking cylinder head gaskets.
Worn or incorrect camshaft.
17
• Proper valve timing/valve train prob-
lem.
•
Restricted exhaust system.
2.
If a problem is found, repair as
necessary.
Go to OBD
System
Check
Was a problem found?
-
Go to Step 18
Index
90-861326--1 MARCH 1999
Page 5D-15
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1998, 1999, 2000, 2001 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
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Marine readers have rated Mercury MerCruiser GM V8 GM V8 454 CID 7.4L and 502 cid 8.2L Marine Engines Service Manual Number 23 5.0 out of 5.0 based on 1 product reviews. Just need the manual. Wrote review. Can't technically review what I haven't seen yet...