喷油器振动的激振源主要是高压燃油的冲击，针阀开启和关闭引起的机械撞击；对应地，喷油器的振动响应由三个瞬态序列组成。本文用小波分析的方法在不同尺度下近似测得的振动信号，并由近似信号估计了喷油正时的参数。为实现柴油机燃油系的自动诊断提出了一种新方法。 Injector vibration excitation source is mainly the impact of high-pressure fuel, needle valve opening and closing caused by the mechanical impact; Correspondingly, the injector vibration response consists of three transient series. In this paper, the wavelet analysis method is used to approximate the measured vibration signals at different scales and the approximate parameters are used to estimate the parameters of injection timing. A new method is proposed for the automatic diagnosis of diesel fuel system.