1. What is Fuel Injector Duty Cycle?

The fuel injector duty cycle represents the percentage of time the injector is open during one complete engine cycle. It's a critical parameter for fuel delivery and engine performance.

2. How Does the Calculator Work?

The calculator uses the duty cycle equation:

Where:

• Pulse Width — Duration the injector is open (in milliseconds)
• Cycle Time — Total time for one complete engine cycle (in milliseconds)

Explanation: The equation calculates what percentage of the total cycle time the injector is actually open and delivering fuel.

3. Importance of Duty Cycle Calculation

Details: Monitoring duty cycle helps prevent injector overuse (typically should stay below 80-85% for safety), optimize fuel delivery, and diagnose fuel system issues.

4. Using the Calculator

Tips: Enter pulse width and cycle time in milliseconds. Both values must be positive numbers. For RPM-based calculations, first convert RPM to cycle time.

5. Frequently Asked Questions (FAQ)

Q1: What is a safe duty cycle limit?
A: Most experts recommend staying below 80-85% to allow sufficient time for the injector to close completely between pulses.

Q2: How does RPM affect duty cycle?
A: Higher RPM means shorter cycle times, which increases duty cycle for the same pulse width. This is why duty cycle becomes critical at high RPM.

Q3: What happens if duty cycle exceeds 100%?
A: The injector would be held open continuously, which can lead to poor fuel atomization, engine damage, and injector failure.

Q4: How do I measure pulse width and cycle time?
A: Use an oscilloscope or automotive diagnostic tool that can read injector pulse width. Cycle time can be calculated from RPM (Cycle Time = 120,000/RPM for 4-stroke).

Q5: Does duty cycle affect fuel economy?
A: Yes, higher duty cycles at given RPMs indicate more fuel is being delivered, which affects fuel consumption rates.