161
Fuel System
Fuel System Tests
7
Make sure the pickup is attached to only one wire.
Flashes on the timing light indicate current in the
circuit is being switched by the EMM. The
Dynamic Tests screen allows the control signal to
be turned off to a particular injector.
IMPORTANT: Some timing lights may not flash
consistently at cranking speeds. Always check the
orientation of the timing light pickup and the oper-
ation of the timing light.
Results:
No light activation on any injector wires (outboard
cranks and starter turns flywheel):
• Check stator input to EMM, CPS operation, and
all grounds and wiring connections.
• Eliminate all other possibilities to isolate a faulty
EMM.
Irregular or no light activation on some injector
wires:
• Test the resistance of individual injector circuits
between the injector connector and injector con-
trol wire at the EMM.
• Check battery cable connections.
• Make sure all grounds are clean and tight.
• See Fuel Injector Resistance Test on p. 167.
Steady light activation on all injector wires and
consistent voltage readings, EMM injector control
function is good:
• Use the diagnostics software Dynamic Fuel Test
to isolate a faulty cylinder. See Dynamic Tests
on p. 108.
Refe
r to Fuel System Pressure Tests on p. 160.
Mechanical Fuel Pump Pressure Test
Remove the Oetiker clamp at the vapor separator
inlet. Then remove the hose from the vapor sep-
arator.
Temporarily install a 0 to 15 psi (0 to 103 kPa)
Fuel Pressure Gauge, P/N 5006397 or equivalent,
between the short hose and the vapor separator
inlet.
Prime the fuel system and check for leaks. START
the outboard and run at idle speed. Hold the
gauge level with inlet fitting and monitor the gauge
for pressure reading.
Pressure should stabilize and gauge must not
indicate less than 4 psi (27 kPa).
Results:
Normal pressure
• Perform the Fuel Lift Pump Vacuum Test on
p. 163. Make sure no air leaks or restrictions
exist in the fuel supply hose or boat fuel system.
Low pressure
• Check pulse hoses and fittings for restrictions.
• Perform the Fuel Lift Pump Vacuum Test on
p. 163. Make sure no air leaks or restrictions
exist in the fuel supply hose or boat fuel system.
Dynamic Tests Screen
008115
1. Oetiker clamp
2. Short hose
009595
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