Dodge RAM 1500 1998 Owner's Manual page 1644

DR
FUEL INJECTOR (Continued)
1 - HIGH-PRESSURE CONNECTOR (TO FUEL INJECTOR)
2 - O-RING
3 - CONNECTOR RETAINER
The torquing force of this threaded nut (fitting)
provides a sealing pressure between the fuel line con-
nector and the fuel injector. Retaining nut torque
is very critical. If the nut (fitting) is under torqued,
the mating surfaces will not seal and a high-pressure
fuel leak will result. If the fitting is over torqued, the
connector and injector will deform and also cause a
high-pressure fuel leak. This leak will be inside the
cylinder head and will not be visible. The result will
be a possible fuel injector miss-fire and low power, or
a no-start condition.
The fuel injectors use hole type nozzles. High-pres-
sure flows into the side of the injector, the ECM acti-
vates the solenoid causing the injector needle to lift
and fuel to be injected. The clearances in the nozzle
bore are extremely small and any dirt or contami-
nants will cause the injector to stick. Because of this,
it is very important to do a thorough cleaning of any
lines before opening up any fuel system component.
Always cover or cap any open fuel connections before
a fuel system repair is performed.
Each fuel injector connector tube contains an edge
filter that is designed to beak up small contaminants
before entering the fuel injector. The edge filters
are not a substitute for proper cleaning and
Fig. 15 HIGH-PRESSURE CONNECTOR
covering of all fuel system components during
repair.
cylinder head with a 1.5mm thick copper shim (gas-
ket). The correct thickness shim must always be re-
installed after removing an injector.
injection. The injector needle valve is immediately
closed and fuel flow into the combustion chamber is
stopped. Exhaust gases are prevented from entering
the injector nozzle by the needle valve.
REMOVAL
CAUTION: Refer to Cleaning Fuel System Parts.
injectors are used (Fig. 14). The injectors are verti-
cally mounted into a bored hole in the top of the cyl-
inder head. This bored hole is located between the
intake/exhaust valves. High-pressure connectors (Fig.
15), mounted into the side of the cylinder head, con-
nect each fuel injector to each high-pressure fuel line.
both batteries. Cover and isolate ends of cables.
FUEL INJECTION - DIESEL
4 - FUEL RAIL
5 - HIGH-PRESSURE FUEL LINES
6 - LOCATING PINS
The bottom of each fuel injector is sealed to the
Fuel pressure in the injector circuit decreases after
Six individual, solenoid actuated high-pressure fuel
(1) Disconnect both negative battery cables from
(2) Remove breather assembly.
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