故障现象一辆金杯车(装配新晨491多点燃油喷射发动机),累计行驶里程约为23万km,出现发动机动力不足的现象。故障诊断首先验证故障现象。起动发动机,怠速运转正常,但缓慢加速的过程中发动机出现轻微抖动,而且提速很慢;急加速时,发动机抖动严重,而且发动机工作声音发闷,好像点火时间过迟;路试时发现,该车在加挡加速时,发动机运转无力,提速很慢。根据故障现象判断,故障属于典型的发动机动力不足的症状。 Failure phenomenon A Jinbei car (assembly 491 more morning fuel injection engine), the cumulative mileage of about 230,000 km, the engine power shortage phenomenon. Troubleshooting First verify the symptoms. Start the engine, idling normal operation, but slow acceleration of the engine appeared slight jitter, and speed is slow; acute acceleration, the engine jitter serious, and the engine sound boring, as if the ignition time is too late; road test found that the When the car is accelerating, the engine runs weakly and the speed is slow. According to the phenomenon of failure to determine, the fault belongs to a typical lack of engine power symptoms.