发动机怠速不良故障现象表现形式有:怠速转速过高,怠速转速过低,怠速抖动

发动机怠速不良故障现象表现形式有:怠速转速过高,怠速转速过低,怠速抖动,怠速转速忽高忽低等,其中怠速抖动是发动机怠速不良最常见的表现形式,也是汽车发动机最常见故障之一。故障发生时往往在发动机怠速工况时产生低频率异常振动现象。出现抖动时，可以通过观察发现发动机的横向摆动明显加大噪声加大，并往往伴随怠速不稳，使车内的驾乘人员感到不舒适，而随着加大油门使发动机转速升高后，发动机抖动现象便减弱或消失。由于发动机怠速抖动会影响发动机的性能，降低其可靠性与使用寿命，增加了功率损耗。如不及时维修，会使发动机性能进一步恶化，有可能导致更大的故障。<br>本文针对电控发动机怠速抖动故障形成机理及原因进行比较详细分析,并且提出比较合理的故障诊断方法。

The manifestations of bad idle speed of engine include: too high idle speed, too low idle speed, idle speed jitter, high idle speed and low idle speed, among which idle speed jitter is the most common manifestation of bad idle speed of engine and one of the most common faults of automobile engine. When the fault occurs, low frequency abnormal vibration often occurs in idle condition of engine. When shaking occurs, it can be observed that the lateral swing of the engine increases significantly, the noise increases, and it is often accompanied by unstable idle speed, which makes the drivers and passengers in the car feel uncomfortable. When the engine speed increases with the increase of accelerator, the phenomenon of engine shaking weakens or disappears. Because the engine idle speed jitter will affect the performance of the engine, reduce its reliability and service life, increase the power loss. If it is not repaired in time, the engine performance will be further deteriorated, which may lead to more serious faults.<br>In this paper, the formation mechanism and causes of electronic control engine idle jitter fault are analyzed in detail, and a more reasonable fault diagnosis method is proposed.<br>

The manifestations of poor engine idle speed are: too high idle speed, too low idle speed, idle speed jitter, high and low idle speed, among which idle speed jitter is the most common manifestation of poor engine idle speed and one of the most common faults of automobile engines. When faults occur, abnormal vibration with low frequency often occurs when the engine is idling. When jitter occurs, it can be observed that the lateral swing of the engine increases obviously and the noise increases, which is often accompanied by unstable idle speed, which makes the drivers and passengers in the car feel uncomfortable. However, when the engine speed increases with increasing the throttle, the engine jitter phenomenon weakens or disappears. Engine idling jitter will affect engine performance, reduce its reliability and service life, and increase power loss. If it is not repaired in time, the engine performance will be further deteriorated, which may lead to more faults.In this paper, the formation mechanism and causes of idle jitter fault of electronically controlled engine are analyzed in detail, and a reasonable fault diagnosis method is put forward.