PIAGGIO PORTER 1.3 16V 2008, Service Manual

Page: 58 / 892

Blow-by ventilation pipe (crankcase vapour re-
covery)
Check that there are no signs of wear or strangling
on the pipe and that it is properly connected.
Fuel closing device during deceleration
The fuel closing device stops fuel supply during deceleration in order to reduce hydrocarbon and CO
emissions, also avoiding catalytic converter overheating.
For HC-ES engines, this device is checked by the program set for the Electronic Control Unit of the
Electronic Fuel Injection.
It is checked when the throttle valve is completely closed and when the engine speed exceeds the set
value.
Besides, the initial and return engine speed to stop fuel is preset according to the temperature of the
engine cooling water.
Air-fuel mixture control system
The closed-loop control system guarantees a suitable air-fuel ratio in the engine. Besides, it guarantees
an optimum quantity of oxygen in the exhaust fumes so as to obtain a high degree of purification of the
three-way catalytic converter.
A = Injector
B = Combustion chamber
C = Front oxygen sensor
D = Three-way catalytic converter
E = Rear oxygen sensor
F = Elect. control unit of the elect. fuel injection
G = Engine coolant temperature sensor
Emission Controlo System
PORTER 1.3 16V
CO EM - 58