Fuel Cut-Off

When ignition is turned off, injectors are de-energized to prevent dieseling. Injectors are not energized if RPM reference pulses are not received by the ECM, even with ignition on. This prevents flooding before starting. Fuel cut-off also occurs at high engine RPM to prevent internal damage to engine. Some models may also cut off fuel injector signals during periods of sudden, closed throttle deceleration (when fuel is not needed).