Efi Fuel Management (Low Pressure Fuel Route) - Mercury 150 EFI Service Manual

EFI Fuel Management (Low Pressure Fuel Route)

Pump does not run
Follow High Pressure Fuel
Route Flow Chart.
No or little fuel flow from vapor
separator.
Inspect float system of vapor
separator.
Results
Fuel flows freely from pulse
pump inlet hose.
See pulse pump removal and
inspection section 3A. Locate
all fragments of failed pump
before reassembly.
90-883728 JULY 2001
Install fuel pressure gauge on to VST pres-
sure port.
Place ignition switch in "OFF" position 30 sec-
onds before testing.
Place ignition switch in "ON" position and
note pressure within 30 seconds (41 to 45 psi;
283 to 310 kPa).
No or low fuel pressure
Perform Vapor Separator Fuel
Delivery Test .
Results
Results
Low or no fuel flow from water
separating inlet hose. Reconnect
hose.
Perform Pulse Fuel Pump De-
livery Test.
Check for restrictions, holes or loose
connections from fuel supply.
Fuel flows freely from vapor
separator.
Follow High Pressure Fuel
Route Flow Chart.
Check fuel/water separator.
Perform Water Separating Fil-
ter Flow Test.
Fuel flows freely from water separat-
ing filter inlet hose. Reconnect hose.
Results
No fuel flow to pulse fuel pump.
FUEL INJECTION
Fuel pressure above 45 psi (310 kPa)
Follow High Pressure Fuel
Route Flow Chart.
Results
Results
Replace water separating filter.
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