Fuel Supply System; Fuel Flow; Engine Fuel Flow - Ford 6.4L Power Stroke Manual

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, and
diesel thermo recirculation valve (DTRM).
• The DTRM controls the flow of fuel returned from the engine
mounted filter through the HFCM. If the fuel being drawn from
the fuel tank is cooler than a specified temperature then return
fuel from the engine is recirculated into the inlet of the pump.
• After the fuel is conditioned by the HFCM, the clean pressurized
fuel is sent to the engine mounted fuel filter assembly where
particles larger than 4 micron are filtered out of the fuel.
• The engine mounted fuel filter assembly also regulates fuel
pressure by releasing excess pressure via a return fuel line
back to the HFCM. The engine mounted fuel filter also contains
air bleed orifices to remove air and return it to the tank.
F uel s up p ly sy ste m

Fuel FlOW

• After the fuel is filtered it is routed to the Internal Transfer Pump (ITP).
• The ITP is located inside the high pressure fuel injection pump
and is used to increase the fuel pressure supplied to the high
pressure fuel injection pump's three (3) internal pistons.
• After the fuel is pressurized it is routed to the high pressure fuel
rails and to the fuel injectors via high pressure fuel supply tubes.
• A Pressure Control Valve (PCV) located in the outlet side
of the high pressure fuel injection pump controls the fuel
pressure by dumping excess fuel into the fuel return line.
• A Fuel Rail Pressure (FRP) sensor located in the
right side fuel rail monitors the fuel pressure.
• Return fuel from the injectors is routed through a drilled passage
from each cylinder head where it is then united with return fuel
from the high pressure fuel injection pump before being sent
to the fuel cooler and back to the engine mounted fuel filter.
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