Dodge dakota 2002 Service Manual page 1783

14 - 86 FUEL INJECTION - DIESEL
FUEL INJECTOR (Continued)
1 - HIGH-PRESSURE CONNECTOR (TO FUEL INJECTOR)
2 - O-RING
3 - CONNECTOR RETAINER
OPERATION
High-pressure fuel is supplied from the injection
pump, through a high-pressure fuel line, through a
fuel pressure limiting valve, into a fuel rail, through
high-pressure lines, through steel connectors and
into the solenoid actuated fuel injector. The ECM
actuates the solenoid causing the needle valve to rise
and fuel flows through the spray holes in the nozzle
tip into the combustion chamber.
Each fuel injector is connected to the fuel rail by a
high-pressure fuel line with a steel connector. This
steel connector is positioned into the cylinder head
and sealed with an o-ring. The connectors are sealed
to the high-pressure fuel lines with fittings. The fer-
rule on the end of the high-pressure fuel line pushes
against the steel connector when the fuel line fitting
is torqued into the cylinder head. This torquing force
provides a sealing pressure between both the fuel
line-to-connector and the fuel connector-to-fuel injec-
tor. The fitting torque is very critical. If the fit-
ting 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
Fig. 15 HIGH-PRESSURE CONNECTOR
visible. The result will be a possible fuel injector
miss-fire and low power.
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 sort of dirt or con-
taminants 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 compo-
nent. Always cover or cap any open fuel connections
before a fuel system repair is performed.
filter that breaks up small contaminants that enter
the injector. The edge filter uses the injectors pulsat-
ing high-pressure to break up most particles so they
are small enough to pass through the injector. The
edge filters are not a substitute for proper
cleaning and covering of all fuel system compo-
nents 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
4 - FUEL RAIL
5 - HIGH-PRESSURE FUEL LINES
6 - LOCATING PINS
The fuel injectors use hole type nozzles. High-pres-
Each fuel injector connector tube contains an edge
The bottom of each fuel injector is sealed to the
Fuel pressure in the injector circuit decreases after
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