Paper presents the general assumptions for an gaseous fuels injector rail diagnosis and calibration with the application vibroacoustic methods, considerably different from used today methodology which typically base on measurements of mechanical dislocation of piston/nozzle, and injector flow rates has been described in the paper.Flow rates, as well as injector actuator stroke measurements are time-consuming and require the use of complex systems. This is what generally disables the methods currently in use from their integration in the continuous control system, especially into OBD. Methodology presented in the paper, based on simultaneous measurements of injector opening time and its vibration, allows an enhanced accuracy of the calibration and diagnosis process. It also shortens the time of calibration since it does not require invasion into mechanical system of injector rail and allows a quick and efficient assessment of its proper operation. The use of this method is likely to meet requirements of accurate fuel dosage in the alternatively gas powered vehicles feeding systems and, in consequence to reduce both fuel consumption and emissions of exhaust gases.Authors do point on the potential of approximated onboard control of the injector rail sections flow rates, with a special attention to the detection of increased flow changes between the injectors of the same rail, prior to the misfire detection.