Article taken from club-s12.org forums. Posted by Magnum

Injector Duty Cycle
To spray the injectors, ECU turns on a given injector for a fixed amount of time every two engine revolutions. The amount of time that an injector stays open is called the injector pulse width. The percentage of the time that the injectors are open is called the injector duty cycle. That is, for every two engine revolutions, the injectors can be open between 0% and 100% of the engine cycle time. When the injector duty cycle is 100%, your injectors are spraying 100% of the time, and you need larger injectors or higher fuel pressure to compensate.