In this paper, we investigate the relationship between fuel injection quantity and voltage and current energy of Bosch system and Delphi system by measuring the high and low voltage waveform, current waveform, fuel injection quantity and fuel pressure of A and J-engines. Waveform measurements are made using the PICO scope and the CDS tester. The injectors of A and J engines were tested under no load condition using injector with normal fuel injection quantity, injector with small fuel injection quantity and injector with many fuel injection quantity. In case of normal injector, A-engine has higher fuel pressure, injection interval time, voltage energy, and current energy than J-engine. The current energy of the A-engine changed linearly compared to that of the J-engine. For over and under injectors, the change in the previous physical quantity was greater for the A-engine than for the J-engine. However, the duration time of maintaining to open the injector is controlled differently, and so the voltage and current energy values are changed, and the change of the current energy is larger than the voltage energy.

This study analyzed by measuring the voltage waveform of the injector intended for operating CRDI diesel vehicle. The cases of the EGR trouble and a EGR normal is considered. 1) The voltage waveform in the case of the normal and trouble, the difference between the maximum voltage was not large, decrease in the number of voltage gated pulses with the increase in engine speed, sustained current remained for this period. 2) The voltage waveform, comparing the case of the normal case and trouble, the size of the maximum voltage, no large change in gate pulse voltage is to be generated than in the case of a defective irregular longer opening time of the injector factor it was possible to know the bad influence on the fuel efficiency.