Systems and methods for improving engine emissions during starting

The invention relates to systems and methods for improving emissions of an internal combustion engine, particularly systems and methods for improving engine emissions during starting. In one example, engine crankshaft acceleration is a basis for estimating an engine air-fuel ratio during engine starting when output of an oxygen sensor may be unavailable. An actual engine air-fuel ratio may be adjusted in response to the estimated engine air-fuel ratio. 本发明涉及用于改善启动期间发动机排放的系统和方法。介绍了用于改善内燃发动机的排放的系统和方法。在个示例中，当氧传感器的输出不可用时，发动机曲轴加速度是估计发动机启动期间发动机空气-燃料比的基础。可以响应于估计的发动机空气-燃料比来调整实际发动机空气-燃料比。