Abstract: An automatic device comprises a complex plane analyzer of a vibration signal of a measured engine unit, electrically coupled via a switch to a computer. The device also comprises a synchronization unit whose inputs are connected to sensors of the angular position of the vehicle engine shaft and transmission shaft, an ignition sensor and a sensor of fuel injection to the cylinders of the vehicle engine. A control input of the unit is coupled to the output of a control unit. There is also an operational parameter measuring unit connected by its inputs to outputs of the synchronization unit and to the output of the control unit. An engine shaft rotational frequency adjustment unit is connected by its input to the control unit and to the synchronization unit and by its output to the actuator controlling fuel supply to the engine cylinders.