SERVICE MANUAL NUMBER 24
FUEL INJECTION SYSTEM TROUBLESHOOTING
Hesitation, Sag, Stumble Symptom
Step
Action
Yes
No
PROCEED TO
Definition: Momentary lack of response as the throttle lever is advanced. Can occur
at all engine speeds. Usually most severe when first starting out. May cause engine
to stall if severe enough.
Was the “On-Board Diagnostic” (OBD)
System Check performed?
1
Step 2
Step 3
OBD
Visual/ Physical
Check
2
3
Was visual/physical check performed?
1.
Check for contaminated fuel.
2. Check water separating fuel filter.
Was a problem found?
Step 4
Step 5
1.
Check or proper fuel pressure while the
condition exists.
4
• Refer to Table A-4 in “General System
Diagnostics” section.
Was a problem found?
1.
Check fuel injectors.
•
Refer to Injector Balance Test in “Test
General System Diagnostics” section.
5
6
Was a problem found?
Step 6
Step 7
1.
Check for proper operation of Ignition Con-
trol (IC) circuit and the Knock Sensor (KS)
circuit.
Was a problem found?
1.
Check integrity of the primary and second-
ary wiring.
2.
3.
Check routing of the wiring.
Check condition of IC module, pick-up coil,
distributor cap, rotor and spark plug wires.
7
8
Was a problem found?
Step 8
1.
Remove spark plugs and check for wet
plugs, cracks. wear, improper gap, burned
electrodes or heavy deposits.
•
Refer to Distributor Ignition System.
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 9
Index
90-861327--1
OCTOBER 1999
Page 5F-13
| 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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