NEXON

1.2L REVOTRON ENGINE

FUEL SYSTEM COMPONENTS

1. Injector

The injector used in this engine is a piezo injector.

This is controlled by the EMS ECU. The timing of

injection and quantity is controlled by the EMS

ECU. It operates at a pressure of 4 bar. It makes

multiple injections.

The piezo actuator is an electrically energized

device that acts similar to a solenoid but is much

more precise. A piezo actuator is a composition of

piezo discs, that when electrically energized,

cause the discs to deform resulting in an

expansion. This expansion results in a

longitudinal motion thus controlling the injector.

When energized, the piezo actuator pushes

downward against the valve piston. The piezo

actuator is returned to its non-energized state via

the ECU switching the polarity of the electrical

feed to the injector.

2. Fuel Rail

It is a fuel reservoir where the fuel is maintained

at a pressure of about 4 bar. The fuel is pumped

into it from the pump and gets delivered to the

injectors through the lines.

3. Fuel Tank and Fuel Tank Unit

The Fuel tank assembly consists of the fuel tank

and the Intank pump. The fuel tank is used to

store the fuel. The Intank pump consists of float

and a sensor. Fuel level sensor assembly

provides the signal to indicate the fuel level in the

tank. As the float arm assembly moves with

respect to the fuel level in tank, resistance at

sensor varies accordingly.

4. Canister

Canister made of high grade Nylon, containing

special dust free activated carbon is used to

adsorb fuel vapours. The lower end of the canister

is open to atmosphere for ventilation. The end is

not really open but there is foam filter. The

purpose of the bottom filter is to protect the

canister from dust and dirt during operation. When

the engine is inoperative (i.e. while parked) fuel

vapours generated inside the fuel tank due to fuel

volatility and temperature variations are passed

into canister through tank pressure valve.

Activated carbon contained inside the canister

adsorbs these vapours.

When the engine is running, the fuel vapours