Dodge RAM TRUCK 1500 1995 Service Manual page 1089

Fig, 12 Connecting Adapter Tool—Typical
(6) Shut engine off.
(7) Pressure should not fall below 24 psi for five
minutes.
(8) If pressure falls below 24 psi, it must deter­
mined if a fuel injector, the fuel module mounted fuel
pressure regulator or a fuel tube/line is leaking,
(9) Again, start engine and bring to normal operat­
ing temperature.
(10) Shut engine off.
(11) Checking for fuel injector leakage: Clamp
off the rubber hose portion of either tool 8539 or 6631
between the disconnected fuel tube (line) and test
port inlet. If pressure now holds at or above 24 psi, a
fuel injector or the fuel rail is leaking.
Checking for fuel pump module or fuel tube
leakage: Clamp off the rubber hose portion of either
tool 6539 or 6631 between the fuel rail and test port
inlet. If pressure now holds at or above 24 psi, a leak
can be found at a fuel tube/line. If no leaks are found
at fuel tubes or lines, replace the fuel pump module.
MECHANI&&-L MALFtm&Tl&NS
Mechanical malfunctions are more difficult to diag­
nose with this system. The powertrain control mod­
ule (PCM) has been programmed to compensate for
some mechanical malfunctions such as incorrect cam
timing, vacuum leaks, etc. If' engine performance
problems are encountered and a diagnostic trouble
code (DTC) is not displayed, the problem may be me­
chanical rather than electronic.
FUEL TUBES/LINES/HOSES AND CLAMPS
Also refer to the proceeding section on Quick-Con­
nect Fittings.
WARNING: TKZ FUEL SYSTEM IS UNDER A CON­
STANT P R E S S U R E (EVEN WiTH THE ENGINE OFF).
BEFORE SIRViCiNG ANY FUEL SYSTEM HOSES, FIT­
TINGS OR LIMES, THE FUEL SYSTEM P R E S S U R E
FUEL DELIVERY SYSTEM—EXCEPT DIESEL 14 - 7
MUST B E RELEASED. REFER TO THE FUEL P R E S ­
SURE R E L E A S E PROCEDURE IN THIS GROUP,
Inspect all hose connections such as clamps, cou­
plings and fittings to make sure they are secure and
leaks are not present. The component should be re­
placed immediately if there is any evidence of degra­
dation that could result in failure.
Never attempt to repair a plastic fuel line/tube. Re­
place as necessary.
Avoid contact of any fuel tubes/hoses with other vehi­
cle components that could cause abrasions or scuffing.
Be sure that the plastic fuel lines/tubes are properly
routed to prevent pinching and to avoid heat sources.
The lines/tubes/hoses used on fuel injected vehicles
are of a special construction. This is due to the higher
fuel pressures and the possibility of contaminated fuel
in this system. If it is necessary to replace these lines/
tubes/hoses, only those marked EFM/EFI may be used.
The hose clamps used to secure rubber hoses on
fuel injected vehicles are of a special rolled edge con­
struction. . This construction is used to prevent the
edge of the clamp from cutting into the hose. Only
these rolled edge type clamps may be used in this
system. All other types of clamps may cut into the
hoses and cause high-pressure fuel leaks.
Use new original equipment type hose clamps.
Tighten hose clamps to 1 N-m (15 in. lbs.) torque.
QUICK-CONNECT FITTINGS
Also refer to the previous Fuel Tubes/Lines/Hoses
and Clamps section.
Different types of quick-connect fittings are used to
attach various fuel system components. These are: a
single-tab type, a two-tab type or a plastic retainer
ring type.
BINGtE-mB TYPE
This type of fitting is equipped with a single pull
tab (Fig. 13). The tab is removable. After the tab is
removed, the quick-connect fitting can be separated
from the fuel system component.
CAUTION: The interior components (o-rings, spac­
ers) of this type of quick-connect fitting are not ser­
viced separately, but new pull tabs are available. Do
not attempt to repair damaged fittings or fuel lines/
tubes. If repair is necessary, replace the complete
fuel tube assembly.
WARNING: THE F U E L S Y S T E M IS UNDER A CON­
STANT P R E S S U R E (EVEN WITH THE ENGINE OFF).
B E F O R E SERVICING ANY F U E L S Y S T E M H O S E S ,
FITTINGS OR LINES, THE F U E L S Y S T E M P R E S ­
S U R E MUST B E R E L E A S E D . R E F E R TO THE F U E L
P R E S S U R E R E L E A S E P R O C E D U R E m THIS
GROUP.