cranking and turning over are one in the same commonly interchanged with one another. Now running engine is different than cranking or turning over.
FSS stops fuel flow into IP IIRC and subsequently the IP cannot compress and inject what is not there. Thus no more running engine or not able to start.
Hope this helps, I can crank my truck and it turns over whilst the FSS is disconnected and it should not start. If the FSS fails this usually causes the NO start. If truck is running and FSS fails it stalls. I"ve not heard of an FSS failing and causing run on or such, not shutting down the engine. However saying I have not heard of FSS failing and not shutting off the engine does not in any way mean it cannot happen. I don't know if it can or cannot, Mel or Russ may be able to speak to that question.
