c. Starting

c. Starting

With the ignition key in the ON position, the electronic control unit supplies the electric pumpfor several moments and acquires the data from the various sensors.

Depending on the coolant temperature sensor (1), the control unit prepares the opening of the butterfly valve via the direct current motor (2). The starting stage is recognized by the control unit when the value of the engine speed detected by the sensor (3) is more than 30 rpm.

With the engine temperature low, the injection times are increased: the injector remains open longer, creating a richer mixture.

With the engine temperature high, the injection times are decreased with a consequent approach to the stoichiometric ratio. (diagram B).

There is also an anti-flooding function in the control unit which, controlled by an internal timer (timer) gradually reduces the enrichment of the mixture when, for any reason, the engine does not start.

During the post-starting stage, the basic injection times, selected by the control unit, are enriched by a function which varies according to the temperature of the engine coolant which is cancelled depending on the time.

The multiplication value is not kept constant for the entire period it is on, but is reduced gradually (by a timer inthe control unit).

During the stage where the engine is warming upa further enrichment of the mixture takes place, dependent on the temperature of the engine coolant, which is not timed and which is added to the post-starting total. This enrichment decreases gradually in a manner which is inversely proportional to the engine temperature.