There is high variety of injectors for spark ignited (SI) engines, especially those fitted with additional aftermarket LPG/CNG fuel system. The tendency is for using injectors with lower electrical resistance, because of the faster opening time. But this rise some difficulties, one of which is the higher current, that pass through injector’s coil. One of the most used method to counter fight that is using special control signal. Experiments are conducted with varying parameters of the control signal and its influence over current through the coil, temperature, injector’s opening and closing time. Results show that not only less current and heating of the coil but also faster operating speed of the injector itself can be achieved, as the modulation of the pulse affects mainly the closing time of the valve needle.