Starting and post-starting

Starting and post-starting

During starting, it is not possible to recognize the engine timing and consequently it is not possible to implement the phased injection.

During the initial revolutions of the engine, an initial full-group injection is carried out (also because the considerable fluctuations in the rotation speed do not allow the injection phase to be calculated correctly) and then the injection becomes the phased type.

The "basic" injection time is increased by a multiplication coefficient for the entire time the engine is driven by the starter motor.

When the engine has been started up, the coefficient is gradually reduced until it disappears after a certain time; the lower the engine temperature, the longer this period.

K: time enrichment coefficient
t: engine temperature function decrease
α: engine driven (crank)
ON: engine started (run)
OFF:

Operation when cold

Under these circumstances there is a natural weakening of the mixture as a result of the reduced evaporation and the strong condensation of the fuel on the internal walls of the intake manifold: in addition, the increased viscosity of the lubrication oil causes an increase in the passive resistance of the engine.

The "basic" injection time is corrected by a multiplication coefficient which depends on the engine temperature and speed.

Operation in full load conditions

This strategy is enabled when the butterfly opening exceeds 70°.

The "basic" injection time is multiplied by a coefficient (depending on the engine speed) equal to around 1.1.