Engine Overspeed Fuel Cut-Off

Engine Overspeed Fuel Cut-Off:

Engine overspeed protection is an ECU controlled function of the differential pressure regulator. Controlled by the fuel control ECU, fuel cut-off 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 fuel control unit 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. Fuel delivery 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.