General Description

General Description

The system controls the engine and all the systems that make it run:

• fuel supply system;
• air supply system;
• engine cooling system;
• exhaust system with catalytic silencer;
• oil vapour recirculation system;
• exhaust gas recirculation system (E.G.R.).

Operation of these systems is optimised by an electronic control system governed by a control unit.

This is a high pressure electronic injection system for fast diesel engines with direct injection.

Its main features are:

• high injection pressures (1350 bar);
• possibility of modulating these pressures between 150 bar up to the maximum operating pressure of 1350 bar, regardless of the engine speed and load;
• capability of working at high engine speeds (up to 6000 rpm);
• injection control precision (advance and length of injection);
• reduction of consumption levels;
• reduction of emissions.

The main functions of the system are the following:

• fuel temperature control;
• engine coolant fluid temperature control;
• injected fuel quantity control;
• idle speed control;
• fuel cut-off during deceleration;
• cylinder balancing control at idle speed;
• anti-sawing control;
• smoke control at the exhaust during acceleration;
• exhaust gas recirculation control (E.G.R.);
• maximum torque limiting control;
• maximum rpm limiting control;
• glow plug control;
• climate control system engagement control;

• auxiliary fuel pump control;
• cylinder position control;
• main and pilot injection advance control;
• injection pressure closed loop control;
• electrical balance control;
• supercharging pressure control;
• self-diagnostics;
• connection with Alfa Romeo CODE control unit.

Operation

The control unit controls the amount of fuel injected, adjusting the line pressure and injection times.

The information processed by the control unit to control the amount of fuel to be injected is the following:

• engine rpm;
• coolant fluid temperature;
• supercharging pressure;
• air temperature;
• intake air quantity;
• battery voltage;
• fuel pressure;
• accelerator pedal position.

Self-diagnostics

The control unit self-diagnostic system checks the signals leading from the sensors comparing them with the allowed limit data and carries out the following

• warning of faults at starting

• warning light on for 4 seconds: indicates testing;
• warning light off after 4 seconds: indicates no fault to components which may affect the values required by antipollution regulations;
• warning light on after 4 seconds: indicates a fault.

• fault signalling when the engine is running:

• warning light on: indicates a fault;
• warning light off: indicates no fault to components which may affect the values required by antipollution regulations.