Research on the Problem of Intermittent Jitter of Cold Idle of Gasoline Engine
After the cold start of the gasoline engine,the catalytic converter needs to reach a higher tem-perature quickly in order to have a certain conversion efficiency.The control strategy at this stage is often to increase the exhaust temperature rapidly by increasing the speed,reducing the ignition advance angle,and thickening the mixture,but it will affect the NVH performance and drivability.In view of the serious jitter problem in the heating stage of the catalytic converter of a gasoline engine,firstly,through the analy-sis and investigation of the source and transmission path,it was confirmed that the poor combustion stabili-ty in the ignition stage was the root cause of the jitter.Then,the relevant hardware was investigated,and the seat vibration and combustion stability under multiple sets of control parameters were scanned and the emission test was carried out to find a set of control parameters that met the emission and NVH perfor-mance standards.Finally,by adjusting the gear speed control strategy,the abrupt drivability problem in the initial stage was solved,so that the performance indicators of the gasoline model under the cold idle reached the standard.