Operation during acceleration

Operation during acceleration

During this stage the control unit increases the quantity of fuel supplied. The "basic" injection time is multiplied by a coefficient depending on the temperature of the engine and the speed of the opening of the accelerator butterfly (avearge value 1.2). If the brisk 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 with increased speed; the subsequent injectors are, on the other hand, increase on the basis of the previously mentioned coefficients.

A: normal injection time
B: injector re-opening (extra-pulse)
C: injection time including enrichment
OFF: engine at stationary speed
ON: engine in transition

Operation during deceleration

During this stage a negative transit 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, the speed and the load conditions at the moment immediately prior to the start of the deceleration.

Operation during cut-off

The cuto-off strategy is implemented when the control unit recognizes the butterfly in the idle position (signal frombutterfly potentiometer) and the engine speed is above 1600 rpm (with the engine warm). The supply to the engine is re-enabled with the recognition of the butterfly in the not closed position or- when the speed goesbelow 1200 rpm (with the engine warm).