What is the normal range for fuel injection pulse width in cars?
2 Answers
The normal range for fuel injection pulse width in cars is between 1.5 to 2.9 milliseconds. The fuel injection pulse width refers to the duration of each fuel injection controlled by the engine's electronic control unit (ECU), and it is a key indicator of whether the fuel injection pump is functioning properly. Methods to address excessive fuel injection pulse width include: 1. Checking whether the oxygen sensor and coolant temperature sensor are aged and replacing them if necessary; 2. Recalibrating the closed-loop data obtained by the ECU, which may require professional testing at a service station. The unit for fuel injection pulse width is milliseconds. A higher displayed value indicates a longer duration for each fuel injection, while a lower value indicates a shorter duration.
From my experience in car repair, the normal range of fuel injection pulse width mainly depends on the engine operating conditions. For example, it typically varies between 2-5 milliseconds at idle, and may reach 8-12 milliseconds under full load. Each vehicle has different designs, and there are significant differences between new and old cars. To check the pulse width, you can use an OBD-II diagnostic tool to read the data—simply connect it to see real-time values. The ECU automatically adjusts based on sensor information to ensure optimal fuel efficiency. Common issues include carbon buildup or clogged injectors causing abnormal increases in pulse width. For instance, exceeding 10 milliseconds indicates increased fuel consumption, which requires timely cleaning or replacement of the injectors. Regular maintenance is key—I recommend inspecting the fuel system every two years to avoid affecting engine performance. In summary, the range isn't fixed, but diagnostic tool data is a reliable reference, and keeping up with vehicle maintenance can prevent unexpected problems.
