Evinrude E-tec 75 HP, Service Manual

Page: 119 / 344

119
SYSTEM ANALYSIS
FUEL DELIVERY
5
FUEL DELIVERY
Refer to Relieving Fuel System Pressure on
p. 168.
Use the
Evinrude
Diagnostics Software program
to review service codes prior to troubleshooting.
Correct all conditions related to service codes
FIRST.
Inspect all fuel hoses, filters, and connections.
Check quality of fuel supply.
Manifold Pressure Test
If the outboard runs, check pressure with the out-
board running. Perform pressure tests outlined in
Fuel Supply on p. 165.
If the outboard does not run, use the primer bulb
to fill the vapor separator. Make sure circulation
pump activates with outboard cranking.
The Fuel Pump test of the diagnostic program can
be used to activate electric fuel pump.
Results:
Pressure test indicates 20 to 30 psi (138 to 207
kPa):
•
Circulation pump output is good. Make sure fuel
system pressure does not fall below 15 psi (103
kPa) after outboard (pump) is OFF for five min-
utes. Leakdown indicates a fuel system leak or
leaking injector.
Low or no pressure, pump runs:
•
Suspect damaged fuel pressure regulator in
vapor separator or faulty circulation pump. Per-
form
Pressure Regulator Test on p. 165.
Pump does not run:
•
Check voltage at pin 1 of fuel pump connector.
Voltage should be 12 V key ON, 55 V cranking
or running.
•
Check voltage at pin 2 of fuel pump connector.
The
EMM
controls the fuel pump ground (brown
wire). Use the fuel pump test of the diagnostic
program to activate the ground control function
of the
EMM
. Connect voltmeter positive lead to
pin 2 and negative meter lead to ground. Acti-
vate Fuel Pump test or run outboard. Voltage
reading should drop slightly as
EMM
connects
the control circuit to ground.
Excessive pressure:
•
Check for restricted pressure regulator in vapor
separator or restricted fuel return manifold.
WARNING
Protect against hazardous fuel spray.
Before starting any fuel system service,
carefully relieve fuel system pressure.
Static Tests Screen 005173