Engine Fuel Flow - Ford 6.0L POWER STROKE Service Procedures And General Diagnostics

F U E L S U P P LY S Y S T E M

Engine Fuel Flow

• The fuel pump, located in the
Horizontal Fuel Conditioning
Module (HFCM), draws fuel from
the fuel tank and through a 10
micron fuel filter.
• The HFCM contains the fuel pump,
filter, water separator, water in fuel
switch, fuel drain, fuel heater, and
diesel thermo recirculation valve
(DTRM).
• The DTRM controls the flow of fuel
returned from the secondary filter
through the HFCM. If the fuel being
drawn from the fuel tank is cool
then return fuel is recirculated into
the pump, if it is warm then return
fuel is sent to the fuel tank
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• After the fuel is conditioned by the
HFCM, the clean pressurized fuel is
sent to the secondary fuel filter
assembly where particles larger
than 4 micron are filtered out of the
fuel.
• The secondary filter assembly also
regulates fuel pressure by releasing
excess pressure via a return fuel
line back to the HFCM.
• It also has an orifice at the top of
the housing in order to bleed air out
of the housing and back to the fuel
tank.
• After the fuel flows through the
secondary filter it is directed to the
two (2) cylinder heads via fuel lines
past the fuel check valves.
• The fuel is directed to the injectors
via passages that are drilled into
the cylinder heads.
• Once the fuel has entered the head
past the check valve, it does not
return to the fuel supply system.
This is called a dead-end fuel
system.
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