故障现象 一辆宝马735轿车,启动后怠速运转时,发动机转速不稳,转速表指针上下晃动,怠速明显游车。 故障分析与诊断 宝马735轿车,装用直列6缸电喷发动机,发动机罩盖为后掀开式。针对怠速不稳这一故障现象,凭经验,我们首先对怠速控制阀、节气门位置传感器进行了清洗调整,未见好转。试车急加油时,总感 Failure phenomenon A BMW 735 sedan, idling after starting, the engine speed instability, the tachometer pointer shaking up and down, idling significantly the car. Failure Analysis and Diagnosis BMW 735 sedan, equipped with inline 6-cylinder EFI engine, the engine cover to open after the way. For idle instability phenomenon, with experience, we first of all idle speed control valve, throttle position sensor was cleaned and adjusted, no improvement. Test fuel, the total feeling