Small naval vessels are equipped with high- and medium-speed engines with low diagnostic compliance. Faults in fuel installations are the most common cause of failure or inability to perform operational scenarios adequately. Identification of injector damage is severe as small engines are not equipped with indicators and thermocouples to measure the overall exhaust gas temperature in the exhaust manifold. The paper presents a vibration method for assessing the technical condition of a fuel installation. The proposed method is non-invasive and allows the indication of a damaged injector within a relatively short time. The paper presents simulation results verified with stand-bed tests. The research aimed to show the sensitivity and uniqueness of vibration symptoms to changes in the technical condition of fuel injection pumps. The conducted experiment confirmed the possibility of using vibration tests in the professional diagnostics of the fuel installation. These results are essential for the use of marine engines that do not have indicator valves.