Study on Fault Diagnosis of Fuel Injection Based on Vibration Signal Analysis of High-pressure Fuel Injection Pipe

An accurate fuel injection advance angle is an important parameter to obtain better fuel combustion index and emission index. Fuel injection advance angle is always deranged because of the wear of the injection nozzle matching parts, which has serious impact on diesel engine performance. How to measure the fuel injection advance angle easily and accurately is a problem for fault diagnosis of high-pressure fuel injection pipe. In this paper, the vibration signals of high-pressure fuel injection pipes’ nozzle of different cylinders with different fuel injection advance angles were measured by external oil pressure sensor. Through the theoretical analyzing and calculating the above-mentioned experimental data, the characteristic curves were established, which described the relationship between the fuel injection advance angles and the vibration characteristic quantities of high-pressure fuel injection pipes’ nozzle. The characteristic curves were the judgment basis of fuel injection system fault diagnosis. It can be applied to diagnose the fault that caused by fuel injection advance angle change which induced by improper adjustment and matching parts abrasion.