Dodge dakota 2002 Service Manual page 1703

14 - 6 FUEL DELIVERY - GAS
FUEL DELIVERY - GAS (Continued)
ADAPTERS, FUEL PRESSURE TEST, 8.0L - #6539
AND/OR #6631
SPANNER WRENCH - #6856
FITTING, AIR METERING - #6714
O2S (OXYGEN SENSOR) REMOVER/INSTALLER -
#C-4907
FUEL FILTER/PRESSURE
REGULATOR
DESCRIPTION
A combination fuel filter and fuel pressure regula-
tor (Fig. 2) is used on all engines. It is located on the
top of the fuel pump module. A separate frame
mounted fuel filter is not used with any engine.
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.
Fig. 2 SIDE VIEW - FILTER/REGULATOR
1 - INTERNAL FUEL FILTER
2 - FUEL FLOW TO FUEL INJECTORS
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - EXCESS FUEL BACK TO TANK
5 - FUEL INLET
6 - RUBBER GROMMET
7 - TOP OF PUMP MODULE
OPERATION
Fuel Pressure Regulator Operation: The pres-
sure regulator is a mechanical device that is not con-
trolled by engine vacuum or the Powertrain Control
Module (PCM).
The regulator is calibrated to maintain fuel system
operating pressure of approximately 339 kPa ± 34
kPa (49.2 psi ± 5 psi) at the fuel injectors. It contains
a diaphragm, calibrated springs and a fuel return
valve. The internal fuel filter (Fig. 2) is also part of
the assembly.
Fuel is supplied to the filter/regulator by the elec-
tric fuel pump through an opening tube at the bot-
tom of filter/regulator (Fig. 2).
The regulator acts as a check valve to maintain
some fuel pressure when the engine is not operating.
This will help to start the engine. A second check
valve is located at the outlet end of the electric fuel
DR