This study examined the repeatability of fuel dosage in a Common Rail injection system under five operating conditions: idling, full engine load, micro-dosing, full injector load, and high-frequency operation. Using an injection waveform indicator, researchers analyzed the dynamic behavior of the injection process, including solenoid valve function and signal waveforms, which were compared to injection pressure buildup. Integral and differential injection characteristics were developed for each condition. Results showed the greatest dosing variability during micro-dosing, with a 6.24% variation in injection volume and 7.81% in pressure. In contrast, full engine load showed minimal variation (0.43% and 1.45%). The study concluded that injector component inertia notably impacts dosing consistency, especially at low pressures or short opening times.