Please correct my initial response.  Sorry.

A first pass at investigating the impression below could be easily done if the controller doubled the fuel flow rate per injector rather than doubling the pulse width when changing from using four injectors to using two injectors.  I believe we could test your idea on our engine stand by making the injector transition and then readjusting the fuel flow manually back to the initial flow rate.  Since the engine stand uses a Floscan fuel flow transducer which does not depend on injector pulse width, the effect of the transition while maintaining constant fuel flow should be evident in the oxygen sensor response.  I’ll add that to the things to try on the next engine stand session.

Steve Boese

A first pass at investigating the impression below could be easily done if the controller cut the fuel flow rather than the pulse width in half when changing from using four injectors to using two injectors.  I believe we could test your idea on our engine stand by making the injector transition and then readjusting the fuel flow manually back to the initial flow rate.  Since the engine stand uses a Floscan fuel flow transducer which does not depend on injector pulse width, the effect of the transition while maintaining constant fuel flow should be evident in the oxygen sensor response.  I’ll add that to the things to try on the next engine stand session.

Steve Boese

I had an intuitive impression that the injected fuel slows the passage of intake air, so shutting off one injector, preferably the one in the bigger intake port, could increase power by providing more air for combustion. If the other injector could flow enough fuel for the required power level?