Chrysler RAM TRUCK 2500 1994 Service Manual page 949

Fig. 12 Connecting Adapter Tool—Typical
(6) Shut engine off.
(7) Pressure should not fall below 24 psi for five
minutes.
(8) I f pressure falls below 24 psi, i t must deter­
mined i f 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 6539 or 6631
between the disconnected fuel tube (line) and test
port inlet. I f pressure now holds at or above 24 psi, a
fuel injector or the fuel rail is leaking.
Checking for fuel pressure regulator o r fuel
tube leakage: Clamp off the rubber hose portion of
either tool 6539 or 6631 between the fuel rail and
test port inlet. I f pressure now holds at or above 24
psi, a leak can be found at a fuel tube/line. I f no
leaks are found at fuel tubes or lines, replace the fuel
filter/fuel pressure regulator.
MECHANICAL MALFUNCTIONS
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. I f 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: T H E F U E L S Y S T E M IS UNDER A CON­
STANT P R E S S U R E ( E V E N WITH T H E ENGINE O F F ) .
B E F O R E SERVICING ANY F U E L S Y S T E M H O S E S ,
FITTINGS O R L I N E S , T H E 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 T H E 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 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 i f there is any evidence of degra­
dation that could result i n failure.
Never attempt to repair a plastic fuel line/tube. Re­
place as necessary.
Avoid contact of any fuel tubes/hoses with other ve­
hicle components that could cause abrasions or scuff­
ing. 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 contami­
nated fuel i n this system. I f i t 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 i n this
system. A l l 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 i n . 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.
SINGLE-TAB 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, s p a c ­
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/quick-connect fitting assembly.