Operation in acceleration conditions

Operation in acceleration conditions

During this stage, the control unit increases the quantity of fuel supplied.

The "basic" injection time is multiplied by a coefficient which depends on the temperature of the engine and the opening speed of the accelerator butterfly (average value 1.2).

If the sharp variation in the injection time is calculated when the injector is already closed, the control unit reopens the injector (extra pulse) in order to compensate the mixture strength as quickly as possible: the subsequent injections are, on the other hand, already increased on the basis of the coefficients mentioned previously.

A: normal injection time

B: injector reopening (extra-pulse)

C: injection time inculding enrichment

OFF: engine at stationary speed

ON: engine in transition

Operation in deceleration conditions

During this stage a negative transition strategy is implemented to decrease the quantity of fuel supplied: the "basic" injection time is multiplied by a coefficient which depends on the temperature of the engine and the engine speed and load conditions in the moment immediately preceding the start of deceleration.

Operation in cut-off conditions

The cut-off strategy is implemented when the control unit recognizes that the butterfly is in the idle position (signal from the butterfly potentiometer) and the engine speed is above 1600 rpm (with the engine warm).

The supply to the engine is re-enabled when the butterfly is in a not closed position or when the engine speed goes below 1200 rpm (with the engine warm).