Multi-Port Injection Fuel System Diagnosis (Continued)
Chart A-7: (2 of 6)
FROM
CHART A-3
(2 OF 4)
NOTE: THE IGNITION MAY HAVE TO BE CYCLED
“ON” MORE THAN ONCE TO OBTAIN MAXIMUM
PRESSURE. ALSO, IT IS NORMAL FOR THE PRESSURE
TO DROP SLIGHTLY WHEN THE PUMP STOPS.
1
•
•
•
•
INSTALL FUEL PRESSURE GAUGE, 91-16850 .
IGNITION “OFF” FOR 10 SECONDS.
IGNITION “ON.” FUEL PUMP WILL RUN FOR ABOUT 2 SECONDS.
NOTE FUEL PRESSURE, WITH PUMP RUNNING, SHOULD BE
34-38
PSI (234-262 kPa) AND HOLD STEADY WHEN PUMP STOPS.
OK
NOT OK
2
3
PRESSURE BUT
NOT HOLDING
PRESSURE BELOW
34 PSI (234 kPa)
PRESSURE ABOVE
38 PSI (262 kPa)
NO
PRESSURE
•
•
START AND IDLE ENGINE AT
NORMAL OPERATING
TEMPERATURE.
PRESSURE SHOULD BE LOWER
BY 3-10 PSI (21-69 kPa).
•
•
IGNITION “OFF.”
•
IGNITION “OFF” FOR
SEE
10
SECONDS.
CHART A-7
4 OF 6
APPLY 12 VOLTS TO FUEL
PUMP CONNECTOR(GRAY
WIRE).
•
•
IGNITION “ON.”
BLOCK FUEL PRESSURE LINE USING
SPECIAL TOOL (SHUT-OFF VALVE)
PRESSURE SHOULD HOLD.
•
LISTEN FOR FUEL PUMP
RUNNING.
OK
NOT OK
•
NO TROUBLE FOUND.
REVIEW THE TROUBLE-
SHOOTING SECTION.
NOT HOLDING
HOLDS
•
•
•
IGNITION “OFF” FOR 10 SECONDS.
IGNITION “ON.”
BLOCK FUEL RETURN LINE USING
SPECIAL TOOL (SHUT-OFF VALVE)
RECHECK PRESSURE.
CHECK:
•
USING AN EXTERNAL
•
LEAKING PUMP FITTINGS,
OR HOSE.
VACUUM SOURCE, APPLY 10
INCHES OF VACUUM TO FUEL
PRESSURE REGULATOR.
•
FAULTY VST PUMP.
•
•
FUEL PRESSURE SHOULD DROP
3-10
PSI (21-69 kPa).
OK
NOT OK
HOLDS
NOT HOLDING
4
FAULTY FUEL PRESSURE
REGULATOR.
LOCATE AND CORRECT
LEAKING INJECTOR(S).
REPAIR VACUUM
SOURCE TO
REGULATOR.
REPLACE
REGULATOR
ASSEMBLY.
PUMP RUNS
CHECK FOR:
PUMP NOT RUNNING
CHECK FOR:
•
•
RESTRICTED FUEL LINE.
DISCONNECTED HOSE
•
•
OPEN WIRE IN CKT 120.
OPEN PUMP GROUND
CKT 150.
IF OK
IF OK
REPLACE ELECTRIC FUEL PUMP.
Index
90-823224--2 796
ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5C-61
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
Manuals are all Important for Technician
This book is invaluable if you do your own repairs. Great book.
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