Mercury MerCruiser MCM 454 Mag MPI Service Manual page 569

FUEL INJECTION SYSTEM TROUBLESHOOTING
Hard Start Symptom (Continued)
15
16
17
18
Index
Page 5D-10
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1. Check for proper operation of the TP
sensor.
2. Check or throttle linkage sticking,
binding or worn causing TP sensor
voltage to be higher than normal.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check for proper operation of the
IAC valve.
Refer to Table A-8 in "General Sys-
tem Diagnostics" section.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check or the following Engine
Mechanical problems:
Low compression.
Leaking cylinder head gaskets.
Worn or incorrect camshaft.
Proper valve timing/valve train prob-
lem.
Restricted exhaust system.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
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.
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?
SERVICE MANUAL NUMBER 23
Go to OBD
System
- Go to Step 16
Check
Go to OBD
System
- Go to Step 17
Check
Go to OBD
System
- Go to Step 18
Check
MerCruiser
Go to OBD
Customer
System
-
Check
90-861326--1 MARCH 1999
Contact
Service