Description of system

DESCRIPTION OF SYSTEM

To further reduce emissions of NOx (nitric oxides) the supply system is fitted with an E.G.R. valve (1). The E.G.R. valve (Exhaust Gas Recirculation) withdraws part of the exhaust gas and returns it to the intake box (4), where it is mixed with the intake air and burnt in the engine.

The E.G.R. valve is operated by the vacuum modulated by the solenoid valve (2) controlled by the MOTRONIC control unit.

The amount of exhaust gas sent to the engine is determined by the MOTRONIC control unit, taking account of the characteristic curve of the E.G.R. control depending on the engine load and speed and on the temperature of the coolant fluid.

Through the MOTRONIC control unit the solenoid valve modulates the vacuum to be sent to the E.G.R. valve for opening.

The E.G.R. valve is not activated at idle speed, in neutral gear and for engine speeds below 2000 rpm. When the engine coolant fluid temperature exceeds 60 °C the E.G.R. valve is operational and it is completely closed at engine speeds in excess of 4600 rpm.