Great Wall GW491QE, Руководство по обслуживанию

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EF.2-21
24.฀Fuel฀filter฀and฀pipe
(a)Function฀ &principal
Fuel฀ filter
-฀฀The฀function฀of฀fuel฀filter฀is฀to฀separate฀foreign฀solid฀materials฀from
fuel;
-฀฀To฀keep฀a฀better฀filtration฀effect,฀and฀prevent฀the฀injection฀nozzle฀from
blocking฀by฀foreign฀materials฀while฀working,฀A฀special฀fuel฀filter฀for
electrical-injection฀shall฀installed฀in฀the฀system;
-฀฀The฀cover฀of฀filter฀must฀be฀with฀sufficient฀strength,฀and฀will฀not
rupture฀due฀to฀fuel฀pressure;
Fuel฀ pipe:
As฀the฀fuel฀working฀pressure฀within฀system฀is฀about฀(250 350)฀kPa,
for฀safety฀purpose,฀the฀selected฀fuel฀pipe฀must฀be฀corrosion฀proof฀against
fuel,฀and฀have฀sufficient฀pressure-withstand฀safe฀coefficient;
Installation
The฀fuel฀filter฀is฀serially฀connected฀to฀an฀oil฀loop฀between฀the฀electrical
fuel฀pump฀and฀the฀fuel-rail฀via฀fuel฀pipe
(b)Failure฀ determination
The฀filter฀has฀been฀blocked,฀or฀it฀has฀insufficient฀fuel฀pressure
(b)Failure฀determination:
-Any฀failure฀on฀injector฀and฀its฀related฀loops฀may฀be฀determined฀by
driving฀the฀injector฀to฀act฀via฀Diagnosis฀Instrument฀(when฀not฀driving);
-Failure฀diagnosed฀by฀the฀system฀may฀be฀read฀out฀from฀aDiagnosis
Instrument
-Blocked฀by฀foreign฀materials;
-฀A฀glue฀film฀is฀formed฀after฀fuel฀evaporation;
-Damaged฀sealing฀ring฀cause฀an฀air฀or฀oil฀leakage;
-Connectors฀loosened,฀and฀wire-harness฀damaged;
-Broken฀coil฀loop฀leads฀to฀a฀non฀oil-injection.
(c)Characteristics฀of฀product
-Working฀temperature฀ -30฀ 125฀
-Min.฀working฀voltage <6฀V
-Coil฀resistance (12.0
0.6)
Delphi฀engine฀management฀systm-Determination฀on฀the
principal฀/utility฀/failure฀of฀key฀system฀parts
23.฀I njector
(a)Function฀&principal:
-The฀injection฀nozzle฀structure฀is฀an฀electromagnetic฀switch฀unit.฀The
coil฀pulled฀out฀from฀two฀electrodes฀will฀connect฀with฀ECM฀and฀power
supply฀respectively฀via฀engine฀wire-harness;฀And฀the฀coil฀is฀controlled฀by
ECM,฀and฀after฀connection฀with฀system฀ground,฀will฀produce฀magnetic
force฀against฀spring฀force,฀fuel฀pressure,฀and฀vacuum฀suction฀force฀of
manifold.฀When฀steel฀core฀is฀lift฀up฀by฀suction฀force,฀fuel฀will฀spray฀from
guiding฀hole฀into฀(in฀a฀form฀of฀fog)฀air฀inlet฀gate฀after฀passing฀through฀the
valve-hole฀sealing฀surface฀on฀a฀same฀structure฀as฀steel฀core;฀After฀a฀power
cut,฀the฀magnetic฀force฀will฀disappear,฀and฀the฀injection฀nozzle฀will฀be
closed.฀Rubber฀sealing฀ring฀installed฀on฀the฀top฀of฀fuel฀injector฀will฀work
with฀fuel-rail฀interface฀to฀form฀a฀secure฀pressure฀oiltightness;฀And
rubbersealing฀ring฀installed฀on฀the฀bottom฀will฀work฀with฀engine฀inlet
manifold฀for฀an฀airtightness
-Wiring฀terminal A฀ -฀ +12V,฀ B฀ -฀ ECM -Installation:฀It฀is฀fixed฀on
the฀inlet฀manifold฀via฀fuel-rail.
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