Fuel System - Sym HD2 125 Service Manual

Fuel System

Injector
System Description
After Key-on, the sensors signal to be sent to the ECU. ECU controls the fuel pump relay to make the
1.
fuel pump operate. If the engine is not started, the fuel pump will be shut down within 2 to 3 seconds in
order to save electricity. Fuel pressure regulator maintains fuel pressure at 294 ± 6kPa (about 3 kg / cm
²). According to the operating conditions and environmental compensation coefficient, appropriate fuel
will be injected. After Key-off or engine stopped operating, the fuel pump stops running.
Fuel impurities filtered by the fuel filter should be cleaned regularly.
2.
When the engine can not be started, do not keep start motor running continuously which may lead to
3.
lack of battery power (less than 10 V) and the fuel pump will not be able to operate. The correct way is
to use a new battery.
Injector
8-hole type injector provides two intake valves fuel injection quantity, enhances the effect of fuel
atomization, and reduces HC emissions. Short-type injector cap can easily fix the injector, receive the fuel
from the fuel pump, and limit injector rotation sliding. The signals from ECU control the fuel pressure
regulator, using the diaphragm and spring to maintain the fuel pressure in 294 ± 6kPa (about 3 kg / cm ²),
and determine the fuel injection quantity by adjusting injection time width under different engine
conditions.
Fuel Pump
Electrical fuel pump is placed inside the fuel tank, powered by the battery and controlled by ECU.
Fuel pressure: 294 ± 6kPa (about 3 kg / cm ²)
To this chapter contents
5. Fuel Injection System
Fuel pump
Fuel pump
ECU
Battery
relay
Power relay
5-5