Abstract: Through the analysis of the failure phenomenon of the idling jitter of the Magotan B8L car, combined with engine system control logic and the auxiliary test of automobile special equipment, the fault diagnosis and elimination of engine idling jitter was completed finally. The faults involve the engine ignition system, intake system and fuel injection system, which are comprehensive and representative. During analysis and diagnosis, the basic idea of engine system fault diagnosis and its control logic was demonstrated and it has certain reference value for teachers and students of vocational colleges and maintenance personnel. At the same time, fault diagnosis ideas and the analysis of fault mechanism have certain reference significance for other aspects of engine fault maintenance.

Key words: Magotan B8L; Engine; Idling jitter; Fault diagnosis

摘要： 通过对迈腾 B8L 轿车怠速抖动的故障现象进行分析，结合发动机系统控制逻辑，利用 汽车专用设备辅助测试，最终完成了发动机怠速抖动的故障诊断与排除。故障涉及发动机点 火系统、进气系统及燃油喷射系统，全面且具有代表性。分析诊断过程，展示了发动机系统 故障诊断的基本思路及其控制逻辑，对职业院校师生和维修人员具有一定的参考价值。同时， 故障诊断思路及故障机理的分析对发动机其他方面的故障维修具有一定的借鉴意义。

关键词: 迈腾 B8L；发动机；怠速抖动；故障诊断