SERVICE MANUAL NUMBER 24
FUEL INJECTION SYSTEM TROUBLESHOOTING
Lack of Power, Sluggish or Spongy Symptom
Step
Action
Yes
No
PROCEED TO
Definition: Engine delivers less than expected power. Little or no increase in speed when
throttle lever is advanced part way.
Was the “On-Board Diagnostic” (OBD)
System Check performed?
1
Step 2
OBD
If possible, compare engine performance with
a similar engine.
Is engine performance close to similar No problem
2
3
4
engine?
found
Step 3
Visual/ Physical
Check
Was visual / physical check performed?
Step 4
1.
Remove and check flame arrestor for dirt,
or for being restricted.
2.
Clean or replace flame arrestor.
Was flame arrestor dirty or restricted?
Step 5
Step 6
1.
Check for contaminated fuel.
5
6
2. Check water separating fuel filter.
Was a problem found?
1.
Check for proper fuel pressure while the
condition exists.
Refer to Table A-4 in “General System
Diagnostics” section.
•
Was fuel pressure 30 psi for EFI or 3–7 psi
for carbureted engines?
Step 7
Step 8
1.
Check for injector driver CKT 467 or CKT
468 for an open.
7
8
Did you find an open?
1.
Check for proper operation of Ignition Con-
trol (IC) circuit and the Knock Sensor (KS)
circuit.
Was a problem found?
Step 9
1.
•
Check for proper ignition voltage output.
Refer to Table A-7 in “General System
Diagnostics” section.
9
Was a problem found?
Step 10
1.
Remove spark plugs, check for wet plugs,
cracks, wear, improper gap, burned elec-
trodes or heavy deposits.
•
Refer to “Distributor Ignition System” in
“Description and System Operation” sec-
tion.
10
NOTE: If park plugs are gas or oil fouled, the
cause of the fouling must be determined before
replacing the spark plugs.
Were spark plugs damaged?
OBD
Step 11
Index
90-861327--1
OCTOBER 1999
Page 5F-9
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 305 CID, Mercury MerCruiser 350 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 Engines Service Manual Number 24 GM V-8 305 CID 350 CID 4.0 out of 4.0 based on 1 product reviews. Great performance engine.
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