故障现象一辆2008年生产的五菱荣光车,搭载B12发动机,行驶里程约为6万km,因线路老化在其他修理厂更换线束后出现加速无力,最高车速只有40 km/h的故障。当时维修人员用故障检测仪进行了检测,并无故障代码,怀疑是燃油压力不足,但更换燃油泵总成后试车,故障依旧,因此向笔者求助。故障诊断接车后试车,发动机怠速平稳,原地急加速,发动机响应略慢且声音沉闷。打开发动机室盖检查,发现点火线圈、分缸线、火花塞均是新的。测量燃油压力,为350 kPa~380 kPa,正常。用故障检测仪进行检查,确实无故障代码;读取发动机数据流,怠速数据无明显异常;急加速试车,发现点火提 Fault phenomenon A 2008 production of the Wuling Rong Guang car, equipped with B12 engine, mileage of about 60,000 km, due to line aging after the replacement of other wiring harness in the ineffective, the maximum speed of only 40 km / h failure. At that time, maintenance personnel with the fault detector was tested, no fault code, suspected fuel pressure shortage, but after replacing the fuel pump assembly test, the fault remains the same, so I asked for help. Troubleshooting After the car was put on a test run, the engine was idling at a steady speed, accelerated in situ, and the engine responded slowly and dullly. Open the engine room cover inspection and found that the ignition coil, cylinder line, spark plugs are new. Measuring fuel pressure, 350 kPa ~ 380 kPa, normal. Check with the fault detector, indeed no fault code; read the engine data stream, idling data no significant abnormalities; accelerated test and found ignition