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DIESEL ENGINE INFORMATION
The Diesel engine fuel system consists of:
•an engine-mounted secondary fuel filter
•frame-mounted Horizontal Fuel Conditioner Module (HFCM)
•a unit injector for each cylinder
The HFCM acts as a primary fuel filter/water separator which removes
both water and impurities from the fuel. The engine-mounted fuel filter
and the HFCM filter should be changed at the recommended service
interval. Refer to theScheduled maintenance guidesection of this
manual for more information.
The HFCM should be drained at
regular intervals or when the
WATER IN FUEL light illuminates in
the instrument cluster.
The fuel injectors are located in the center of the combustion chambers
in the cylinder head between the rocker arm assemblies. The glow plug
system and fuel injection system are controlled through the Powertrain
Control Module (PCM) and Fuel Injection Control Module (FICM).
Fuel is drawn from the fuel tank by a frame-mounted electric fuel pump.
The fuel pump provides pressurized fuel to the engine and is
electronically controlled by the fuel pump PCM relay. The fuel pump
contains a pressure relief valve for overpressure protection in the event
of restricted flow.
Lubrication system
It is important to change the engine oil at the recommended service
intervals, because oil viscosity is important in maintaining the oil
pressure required to actuate the fuel injectors. Extended oil change
intervals can negatively affect engine performance, fuel economy and
engine life. Refer to the engine oil specification chart located under
Engine oil specificationsin theGeneral maintenance information
chapter.
Diesel information
4
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WAIT TO START
With the key in the ON position, the
WAIT TO START light will illuminate
if glow plug heat is necessary as a starting aid. Wait until the light goes
off before starting. The light should always illuminate briefly, when the
ignition key is in the ON position. If the light does not illuminate, there
may be a problem. Refer to theStartingchapter in this guide. After the
engine starts, the light should remain off.
WATER IN FUEL
During refueling, it is possible for
water-contaminated diesel fuel to be
pumped into your tank. Your vehicle fuel system is equipped with an
HFCM to remove water from the fuel. The WATER IN FUEL light will
illuminate when the ignition is turned to START (as part of the light
function check) and when the HFCM has a significant quantity of water
in it.
If the light illuminates when the engine is running, stop the vehicle as
soon as safely possible, shut off the engine, then drain the HFCM. Refer
to theGeneral maintenance informationchapter for drain procedure.
Allowing water to stay in the system could result in extensive damage to,
or failure of, the fuel injection system.
Warning lights
8
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Diesel fuel must not be stored in a galvanized container. The fuel will
dissolve the zinc in a galvanized container. The zinc will then remain in
solution until it is run through the engine where it will be deposited in
the fuel injectors causing expensive-to-repair damage.
Diesel fuel dispensing nozzle fill rate
Truck stops have pumps and nozzles designed for larger, heavy-duty
trucks. When refueling at truck stops: if the nozzle shuts off repeatedly
when refueling, wait 5–10 seconds; then use a slower rate of flow (don’t
depress the nozzle trigger as far).
This truck is equipped with a fuel fill pipe which is able to accept fuel up
to 20 gallons per minute from an 1 1/8 inch fuel dispensing nozzle.
Pumping fuel at greater flow rates may result in premature nozzle
shut-off or spitback.
HORIZONTAL FUEL CONDITIONING MODULE (HFCM) (FUEL
FILTER/WATER SEPARATOR)
The vehicle is equipped with a Horizontal Fuel Conditioning Module
(HFCM) located on the frame-rail under the driver-side floorboard near
the transmission.
Water should be drained from the
module assembly whenever the
warning light comes on. The WATER
IN FUEL light will come on when
approximately 100 cc (0.2 pints) of water accumulates in the module.
Replace the fuel filters with Ford Part No. 3C3Z-9N184–CA. This part
number includes filters and seals for both the engine-mounted and
frame-mounted filters.
DRIAINING THE HFCM AND CHANGING THE FUEL FILTERS
Your vehicle is equipped with two fuel filters; one mounted on top of the
engine and the other, the HFCM, mounted inside the frame rail under
the driver-side floorboard near the transmission. Both filters should be
replaced at the same time.
HFCM drain procedure
1. Stop the vehicle andshut offthe engine.
The vehicle must be stopped with the engine off when draining
the HFCM. Fuel may ignite if separator is drained while the
engine is running or vehicle is moving.
General maintenance information
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