Mercury MerCruiser MCM 454 Mag MPI Service Manual page 581

FUEL INJECTION SYSTEM TROUBLESHOOTING
Cuts Out, Misses Symptom (Continued)
6
7
8
9
10
Index
Page 5D-22
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1. Check fuel injectors.
Refer to Injector Balance Test in
"General System Diagnostics" sec-
tion.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check for proper spark at each cylin-
der.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check the spark plugs for the follow-
ing:
Insulator cracks.
Improper gap.
Burned electrodes.
Heavy deposits.
NOTE: If spark plugs are gas or oil
fouled, the cause of the fouling must be
determined before replacing the spark
plugs.
2. If a problem is found, repair as nec-
essary
Was a problem found?
1. Check engine mechanical for the fol-
lowing conditions.
Low compression.
Sticking or leaking valves.
Bent push rods
Worn rocker arms.
Broken valve springs.
Worn camshaft lobe(s).
Incorrect valve timing.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check Intake and exhaust man-
ifold(s) for casting flash.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
SERVICE MANUAL NUMBER 23
Go to OBD
System
- Go to Step 7
Check
Go to OBD
System
- Go to Step 8
Check
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
90-861326--1 MARCH 1999