Chrysler RAM TRUCK 2500 1994 Service Manual page 948

PLASTIC
LOCKNUT
FUEL FILTER/
FUEL PRESSURE
REGULATOR
FUEL
SUPPLY
CONNECTION
TOP OF
FUEL
TANK
PRESSURE RELIEF/
ROLLOVER VALVE
AUXILIARY
FUEL SUPPLY
FITTING
(SOME ENGINES)
RUBBER GROMMET
FRONT OF
TANK
PUMP/GAUGE
ELEC. CONNECTION
J9414-32
Fig. 10 Fuel Filter/Fuel Pressure Regulator—Typical
(1) Remove (unscrew) the protective plastic cap
from the pressure test port on the fuel rail (Fig. 9).
On the 8.0L V-10 engine, this test port is located at
the front of the engine. Connect the 0-414 kPa (0-60
psi) fuel pressure gauge (from Gauge Set 5069) to
test port pressure fitting on fuel rail (Fig. 11).
FUEL PRESSURE
TEST G A U G E
J9214-28
Fig. 11 Fuel Pressure Test—Typical
(2) Note pressure gauge reading. Fuel pressure
should be approximately 241-310 kPa (35-45 psi) at
idle.
(3) I f pressure is at O psi, connect DRB scan tool
and refer to operating instructions i n the appropriate
Powertrain Diagnostics Procedures service manual.
I f operating pressure is above 45 psi, fuel pump is
OK. Replace fuel filter/fuel pressure regulator assem­
bly.
FUEL PUMP CAPACITY TEST—GAS POWERED
ENGINES
Before performing this test, verify fuel pump pres­
sure by performing the previous tests.
(1) Release the fuel system pressure from fuel sys­
tem. Refer to the previous Fuel Pressure Release
Procedure i n this group.
(2) Disconnect the fuel supply line at fuel rail.
On the 8.0L V-10 engine, the fuel line-to-fuel rail
connection is made at the rear of the engine. Refer to
Fuel Tubes/Lines/Hoses and Clamps i n this section of
the group for procedures. Remove air cleaner housing
before tool connection.
(3) Connect Fuel Line Pressure Test Adapter Tool
number 6631 (3/8 in.), or number 6539 (5/16 in.) into
the disconnected fuel supply line (tube). Insert the
other end of Adapter Tool 6631 or 6539 into an ap­
proved gasoline container.
(4) To activate the fuel pump and pressurize the
system, obtain the DRB scan tool. Refer to the appro­
priate Powertrain Diagnostic Procedures service
manual for DRB operation.
(5) A good fuel pump will deliver approximately 2
liters of fuel per minute.
FUEL PRESSURE LEAI DOWN TEST—GAS
POWERED ENGINES
ENGINE OFF
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short pe­
riod of time may be caused by:
• Fuel pressure bleeding past a fuel injector(s).
• Fuel pressure bleeding past the check valve i n the
fuel filter/fuel pressure regulator.
(1) Disconnect the fuel inlet line at fuel rail. On
the 8.0L V-10 engine, the fuel line-to-fuel rail connec­
tion is made at the rear of the engine. Refer to Fuel
Tubes/Lines/Hoses and Clamps i n this section of the
group for procedures. Remove air cleaner housing be­
fore tool connection.
(2) Connect Fuel Line Pressure Test Adapter Tool
number 6539 (5/16 in.), or Adapter Tool number 6631
(3/8 in.) between the disconnected fuel line and fuel
rail (Fig. 12).
Adapter Tool connection on the 8.0L V-10 engine is
made at rear of engine.
(3) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
either tool 6631 or 6539. The fittings on both tools
must be in good condition and free from any
small leaks before performing the proceeding
test.
(4) Start engine and bring to normal operating
temperature.
(5) Observe test gauge. Normal operating pressure
should be 241-310 kPa (35-45 psi).