故障现象一辆行驶里程约为5.6万km的东风悦达起亚千里马轿车(配备G4ED发动机和自动变速器),出现发动机有时怠速抖动严重,坐在驾驶室内可以感觉到车身明显在振动的故障,但发动机加速行驶时工作正常。故障诊断经过了解得知,该车在出现上述故障前不久刚刚进行了维护,清洗过怠速阀和节气门。连接故障检测仪进行检测,无故障代码储存;接着读取数据流,也没有发现明显的异常。根据上述故障现象和检测,初步判断为 Trouble phenomenon A mileage of about 56,000 km of the Dongfeng Yueda KIA Maxima sedan (with G4ED engine and automatic transmission), sometimes the engine idling jitter serious, sitting in the cab can feel the obvious vibration of the body failure, but the engine When working at speed, it works fine. Troubleshooting Knowing that the car just appeared shortly before the failure of the maintenance, cleaning the idle valve and throttle. Connect the fault detector for testing, trouble-free code storage; then read the data stream, did not find any significant exception. According to the above symptoms and testing, initially judged as