Jeep Cherokee 2000 Service Manual - page 1228
FUEL SYSTEM PRESSURE WARNING
DESCRIPTION
WARNING: HIGH–PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 45,000 KPA (6526 PSI).
USE EXTREME CAUTION WHEN INSPECTING FOR
HIGH–PRESSURE
FUEL
LEAKS.
INSPECT
FOR
HIGH–PRESSURE FUEL LEAKS WITH A SHEET OF
CARDBOARD
(Fig.
1).
HIGH
FUEL
INJECTION
PRESSURE CAN CAUSE PERSONAL INJURY IF
CONTACT IS MADE WITH THE SKIN.
FUEL TANK
DESCRIPTION
The fuel tank and tank mounting used with the
diesel powered engine is the same as used with gas-
oline powered models, although the fuel tank module
is different.
The fuel tank contains the fuel tank module and
one rollover valve. Two fuel lines are routed to the
fuel tank module. One line is used for fuel supply to
the fuel filter/water separator. The other is used to
return excess fuel back to the fuel tank.
The fuel tank module contains the fuel gauge elec-
trical sending unit. An electric fuel pump is not
used with the diesel engine.
FUEL TANK MODULE
DESCRIPTION
An electric fuel pump is not attached to the fuel
tank module for diesel powered engines. Fuel is
drawn by the fuel injection pump.
The fuel tank module is installed in the top of the
fuel tank. The fuel tank module contains the follow-
ing components:
•
Fuel reservoir
•
Electric fuel gauge sending unit
•
Fuel supply line connection
•
Fuel return line connection
•
Wire harness
•
Fuel inlet filter (Strainer)
FUEL GAUGE SENDING UNIT
DESCRIPTION
The fuel gauge sending unit is attached to the side
of the fuel pump module. The sending unit consists of
a float, an arm, and a variable resistor (track). The
track is used to send an electrical signal used for fuel
gauge operation.
As the fuel level increases, the float and arm move
up. This decreases the sending unit resistance, caus-
ing the PCM to send a signal to the fuel gauge on the
instrument panel to read full. As the fuel level
decreases, the float and arm move down. This
increases the sending unit resistance, causing the
PCM to send a signal to the fuel gauge on the instru-
ment panel to move toward empty.
FUEL FILTER/WATER SEPARATOR
DESCRIPTION
The fuel filter/water separator assembly is located
in the engine compartment near the strut tower (Fig.
2).
The combination fuel filter/water separator pro-
tects the fuel injection pump by helping to remove
water and contaminants from the fuel. Moisture col-
lects at the bottom of the filter/separator in a plastic
bowl.
The fuel filter/water separator assembly contains
the fuel filter, fuel heater element, and water drain
valve.
For information on the fuel heater, refer to Fuel
Heater in this group.
Refer to the maintenance schedules in Group 0 in
this manual for the recommended fuel filter replace-
ment intervals.
For periodic draining of water from the bowl, refer
to Fuel Filter/Water Separator Removal/Installation
in this group.
Fig. 1 Typical Fuel Pressure Test at Injection Pump
1 – FITTING
2 – HIGH PRESSURE LINE
3 – CARDBOARD
14 - 2
FUEL SYSTEM—2.5L DIESEL ENGINE
XJ
DESCRIPTION AND OPERATION (Continued)