Dodge 2000 DURANGO Service Manual page 722

14 - 2 FUEL SYSTEM
DESCRIPTION AND OPERATION (Continued)
FUEL DELIVERY SYSTEM
DESCRIPTION
The fuel delivery system consists of:
• the fuel pump module containing the electric
fuel pump, fuel filter/fuel pressure regulator, fuel
gauge sending unit (fuel level sensor) and a separate
fuel filter located at bottom of pump module
• fuel tubes/lines/hoses
• quick-connect fittings
• fuel injector rail
• fuel injectors
• fuel tank
• fuel tank filler/vent tube assembly
• fuel tank filler tube cap
• accelerator pedal
• throttle cable
OPERATION
Fuel is returned through the fuel pump module
and back into the fuel tank through the fuel filter/
fuel pressure regulator. A separate fuel return line
from the engine to the tank is not used.
The fuel tank assembly consists of: the fuel tank,
fuel pump module assembly, fuel pump module metal
lockring and gasket, and rollover valve (refer to
Group 25, Emission Control System for rollover valve
information).
A fuel filler/vent tube assembly using a pressure/
vacuum, 1/4 turn fuel filler cap is used. The fuel
filler tube contains a flap door located below the fuel
fill cap.
Also to be considered part of the fuel system is the
evaporation control system. This is designed to
reduce the emission of fuel vapors into the atmo-
sphere. The description and function of the Evapora-
tive Control System is found in Group 25, Emission
Control Systems.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module on all models/all engines is
installed in the top of the fuel tank (Fig. 1). The fuel
pump module contains the following components
(Fig. 2):
• A combination fuel filter/fuel pressure regulator
• Electric fuel pump
• Fuel pump reservoir
• A separate in-tank fuel filter (at bottom of mod-
ule)
• Fuel gauge sending unit (fuel level sensor)
• Fuel supply line connection at filter/regulator
• A metal lockring to retain pump module to fuel
tank
• A gasket between tank flange and module
The fuel gauge sending unit (fuel level sensor), and
pick-up filter (at bottom of module) may be serviced
separately. If the electrical fuel pump requires ser-
vice, the entire fuel pump module must be replaced.
Fig. 1 Fuel Pump Module/Fuel Tank (Top View)
1 – FUEL PUMP MODULE
2 – FRONT ROLLOVER VALVE
3 – FUEL FILTER/FUEL PRESSURE REGULATOR
4 – FUEL TANK
5 – EVAP LINE
6 – REAR ROLLOVER VALVE
OPERATION
Refer to Fuel Pump, Fuel Filter/Fuel Pressure Reg-
ulator and Fuel Gauge Sending Unit.
FUEL PUMP
DESCRIPTION
The fuel pump is located inside of the fuel pump
module. A 12 volt, permanent magnet, electric motor
powers the fuel pump.
OPERATION
Voltage to operate the electric pump is supplied
through the fuel pump relay.
Fuel is drawn in through a filter at the bottom of
the module and pushed through the electric motor
gearset to the pump outlet.
Check Valve Operation: The pump outlet con-
tains a one-way check valve to prevent fuel flow back
into the tank and to maintain fuel supply line pres-
sure (engine warm) when pump is not operational. It
is also used to keep the fuel supply line full of gaso-
line when pump is not operational. After the vehicle
has cooled down, fuel pressure may drop to 0 psi
(cold fluid contracts), but liquid gasoline will remain
in fuel supply line between the check valve and fuel
DN