Components Description Of Efi - Sym ATTILA RS-21 EFi 150 Service Manual

Components Description Of EFi

This chapter Contents
4. FUEL INJECTION SYSTEM
ECU (Electronic Control Unit):
¡ E Powered by DC 8~16V, and has 22 terminals connector on the unit.
¡ E The hardware component consists of an 8-bite computer that be its
control center. It contains the functional circuit interface of engine
condition sensing and the driving actuator for the by-pas valve, fuel
injector, and fuel pump, as well as transistor ignition coil.
¡ E Its major software is a monitor strategy operation program that
includes with controlling strategy, MAP and self-diagnosis programs.
Fuel Injector:
¡ E Powered by DC 8~16V, and has 2 terminals connector on the
injector.
¡ E Its major component is the solenoid valve of high resistance driven by
voltage.
¡ E The two terminals are connected to power source and ground
respective. It is controlled by ECU to decide the injection timing, and
the injector pulse width. Working with 4-valve engine, the unique
2-hole designed injector can provide each intake valve with suitable
fuel quantity to reduce HC emission.
Fuel Pump:
¡ E Powered by DC 8~16V, and has 2 terminals connector on the pump.
¡ E The two terminals are connected to power source and ground
respective. The ECU is to control and manage the operation of fuel
pump through electrical power.
¡ E Its major component is a driving fan pump that equipped with a low
electrical consuming DC motor. Powered by 12V voltage and keep
fuel pressure inside the fuel pump in 2.5 bar which can offer 14 liter
fuel per hour.
¡ E The fuel pump is located inside of the fuel tank, and installed a filter in
front of its inlet so that can prevent from foreign materials sucking into
the fuel pump to damage it and the fuel injector.
By-pass Valve for Idle Speed:
¡ E Powered by DC 8~16V, and has 2 terminals connector on the pump.
¡ E The two terminals are connected to power source and ground
respective. The ECU is to control and manage the operation of
by-pass valve through electrical power.
¡ E Its major component is the solenoid valve of high resistance driven by
voltage.
¡ E By means of signals from all sensors, ECU outputs a signal to control
the opening angle of the valve so that can adjust air flowing to the
intake manifold through the by-pass valve, and then correct the idle
speed to have engine in normal operation.
Transistor Ignition Coil:
¡ E Powered by DC 8~16V, and has 2 terminals connector on the coil.
¡ E The two terminals are connected to power source and ground
respective. Its major component is the highly transferred rate
transformer.
¡ E Its ignition timing is controlled by computer program. From the signals
of ignition timing, crank position sensor, throttle valve position sensor,
and engine temperature sensor as well as intake temperature sensor,
and correspondence with engine speed, then the ECU decides the
ignition timing properly by means of controlling of primary current in
ON & OFF operation to create the secondary voltage of
25000~30000V. And then, the voltage trigged the spark plug
ignition. Such kind of ignition system not only can enhance engine
performance to max. but also increase fuel consumption efficiency
and improve emission quality.
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