I was looking at the fuel injection schematics of my early 90’s Toyota Corolla with electronic fuel injection, and it appears all 4 of the injectors are controlled by the same electrical signal. I would have guessed the injectors would time their injection with the valves, but it appears they simply all inject at the same time, independent whether the intake valve is open or closed.
Am I correct? Is this the way Toyota fuel injection worked in the early 90’s? Does Toyota do it the same way same now? Or are there fuel injection systems that time the injection – on an injector by injector basis, so each injector has its own control signal – to the respective intake valve now? It seems like this later method might produce better combustion and therefore less pollution and better fuel mileage.