Page 265 - Foton Workshop Manual - Aumark (BJ1099)

ENGINE CONTROL SYSTEM - FUEL INJECTOR 11-39
FUEL INJECTOR

1. Principle of work
Nozzle structure is a ball valve device of magnetic switch. The two poles of the coil
goes through engine harness and connects with the power supply and ECM. After
coil’s grounding continuity controlled by ECM, the magnetic force generated by
the coil overcomes spring force, fuel pressure and manifold vacuum suction and
sucks the valve core, so the fuel can go through the valve hole, shot up through the
guiding hole to intake valve; after cutting the power supply, there is not magnetic 11
force and under the spring force and fuel pressure, the nozzle is closed.
2. Function and installation
Fuel injector, installed at the end of intake manifold, is controlled by ECM and
exactly outputs fuel volume required by system in different operating conditions.
3. Fault phenomenon and judgment method
(a). Fault phenomenon: Poor idling, poor acceleration, failure in starting (being difficult
to start), etc..
(b). General causes for faults:
If there is colloid accumulation inside fuel injector because of the lack of
maintenance, the fuel injector will fail.

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