What Causes Excessive Cold Start Injection Pulse Width in BMW N20 Engine?
1 Answers
Excessive cold start injection pulse width in BMW N20 engine is caused by abnormal sensor signals of the injection pulse width. Concept of Injection Pulse Width: The unit of injection pulse width is milliseconds (ms). A larger displayed parameter value indicates longer opening time of the injector each time, resulting in richer air-fuel mixture for the engine; while a smaller value indicates shorter opening time, leading to leaner air-fuel mixture. Range of Injection Pulse Width: There is no fixed standard for injection pulse width as it varies with engine speed, load, and intake air volume. The ECU calculates or queries the database based on these parameters to determine the specific injection pulse width value, typically ranging between 1.5ms to 2.9ms.