Great Wall GW491QE, Service Manual

Page: 105 / 222

EF.2-20
21.฀Fuel-rail฀assembly
฀Function฀&principal
-฀Fuel-rail฀is฀composed฀of฀fuel฀guide฀pipe,฀pressure฀stabilization
chamber,฀pressure฀adjustor,฀injector,฀and฀some฀components฀used
for฀fixing฀purpose;
-฀Fuel-rail฀has฀provided฀a฀pressure-adjustment฀capacity฀for฀high-
pressure฀fuel,฀a฀pipeline฀for฀flowing฀to฀each฀injection฀nozzle,฀and
a฀fixed฀support฀for฀each฀injection฀nozzle;
-Installation It฀shall฀be฀installed฀on฀the฀inlet฀manifold.
22.฀Oil฀pressure฀adjustor
(a)Function฀&principal
฀-The฀function฀of฀fuel฀pressure฀adjustor฀is฀to฀adjust฀the฀pressure
of฀fuel฀inside฀fuel-rail,฀and
to฀reduce฀the฀fuel-injection฀interference฀from฀following฀aspects:
change฀of฀fuel฀supply฀velocity,฀change฀of฀fuel฀supply฀from฀fuel
pump,฀change฀of฀vacuum฀degree฀inside฀engine฀inlet฀manifold.
And฀the฀fuel฀pressure฀adjustor฀will฀be฀controlled฀by฀an฀interaction
of฀internal฀adjustment฀spring฀against฀the฀vacuum฀degree฀of฀exterior
inlet฀manifold;฀and฀will฀always฀keep฀a฀constant฀oil-pressure
difference฀across฀fuel-rail฀and฀inlet฀manifold.฀Excessive฀fuel฀having
been฀adjusted฀by฀adjustor฀will฀return฀to฀oil฀tank฀via฀fuel฀return
pipe;
-Installation:฀the฀fuel-pressure฀adjustor฀is฀installed฀on฀oneend
offuel-rail.
฀(b)Failure฀determination
Important฀note Either฀of฀following฀determinations฀may฀be
concluded฀based฀on฀that฀the฀whole฀vehicle,฀its฀wire-harness,฀and
other฀system฀parts฀&components฀are฀normal฀in฀function.
- Vacuum-pressure฀adjustment฀pipe฀loosened;
-Sealing฀ring฀damaged;
-Adjustor฀damaged.
(c)Characteristics฀of฀product
Setting฀of฀pressure:฀฀300฀kPa
work฀schematic฀diagram฀for฀fuel-rail฀assembly
fuel฀return
fuel-pressure฀adjustor
fuel-rail
fuel฀inlet
injection
nozzle
inlet฀manifold pressure฀balance฀pipe
Delphi฀engine฀management฀systm-Determination฀on฀the
principal฀/utility฀/failure฀of฀key฀system฀parts
pressure-adjustment฀hole฀on฀manifold
connect฀with฀inlet
manifold
pressure-adjustment฀spring
pressure-adjustment฀membrane
pressure฀fuel
fuel฀return
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