Gilera 633721 Workshop Manual page 192

Injection
EMS injection system
This vehicle is fitted with an integrated injection and ignition system.
Injection is indirect in the manifold through an electro-injector.
Injection and ignition are timed on the 4-stroke cycle using a tonne wheel pivoted on the camshaft control
and a reluctance variation sensor.
Combustion and ignition are managed on the basis of engine revs and throttle valve opening. Further
corrections are made according to the following parameters:
- Coolant temperature.
- Intake air temperature
- Ambient pressure
The system implements an idle feeding correction with cold engine through a Stepper motor on a by-
pass circuit of the throttle valve. The control unit manages the Stepper motor and the injector opening
time, thereby ensuring the idle steadiness and the proper combustion.
In all conditions of use, mixture preparation is managed by modifying the injector opening time.
The fuel supply pressure is kept constant based on the ambient pressure.
The fuel supply circuit consists of:
- Fuel pump
- Fuel filter
- Injector
- Pressure regulator
The pump, the filter and the regulator are placed inside the fuel tank on a single support.
The injector is connected by two pipes provided with quick couplings. This allows obtaining a continuous
circulation, thereby avoiding the risk of fuel boiling. The pressure regulator is situated at the end of the
circuit.
The fuel pump is controlled by the EMS control unit; this ensures the scooter safety
The ignition circuit consists of:
- HV coil
- HV cable
- Shielded cap
- EMS control unit
- Spark plug
The EMS control unit manages the ignition with optimum timing, ensuring the timing on the 4-stroke
cycle (ignition only during compression).
The EMS injection/ignition system manages the engine function according to a pre-set program.
Should any input signals fail, an acceptable working order of the engine is ensured to allow the user to
reach a service station.
Of course, this cannot happen when the rpm-timing signal is missing, or when the failure involves the
control circuits:
INJEC - 192
Nexus 500 euro 3