Injection/ignition system components

INJECTION/IGNITION SYSTEM COMPONENTS

The injection/ignition system is basically made up of wiring, an electronic control unit (I.E. control unit) and the following sensors/actuators:

INJECTION/IGNITION SYSTEM WIRING

The connection between the different system components is achieved by means of a single set of wiring with various type connectors grouped together in special conduits fitted on the engine.

INJECTION/IGNITION ELECTRONIC CONTROL UNIT

It is made up of thick film hybrid circuits and is connected to the electrical wiring by means of a 55 way (or pole) multiple connector.

All the information on the engine operating conditions transmitted by the various sensors flows into the control unit.

By means of this data and with the aid of characteristic programmes written indelibly in its memory, the control unit is capable of achieving the following objectives:

1. Managing the injection time and frequency; in other words, it provides the quantity of fuel calculated for each cylinder with a sequential, timed operation (1-2-4-5-3).
   In practice, the air/fuel ratio should always remain within the optimum value, defined during setting up, in order to limit fuel consumption, reduce harmful exhaust emissions and ensure optimum thermodynamic efficiency for the engine.
2. Electronically controlling the moment of ignition (ignition advance)
3. Controlling the air flow rate at the rotation speed through the specific sensor in order to allow the smooth running of the engine as the environmental parameters and loads applied vary.
4. Detecting, by carrying out the programmes, any operating defects for the different sensors recorded in the RAM and replacing the incorrect data or data not received with replacement values to ensure the operation of the engine even in emergency conditions (RECOVERY).
5. Supplying the Fiat/Lancia Tester, if connected, via the serial line (diagnostic socket) with the data relating to the operating defects detected and memorized.