Engine Overspeed Fuel Cut-Off

Engine Overspeed Fuel Cut-Off:

Engine overspeed protection is an ECU controlled function of the differential pressure regulator, and is determined by the engine speed calculated from the hall sensor signal. When the engine reaches a critical rpm (just before the engines "red-line" rpm), the ECU cuts off the fuel by reversing the polarity of the current to the differential pressure regulator. As soon as the engine speed drops below the critical rpm, the current to the differential pressure regulator is restored to its positive state and fuel delivery returns to normal. The fuel is alternately cut and restored many times each second, at a critical rpm that is just below the engines "redline" limit. This prevents engine overspeed while maintaining torque and horsepower at the critical rpm.