Proper way to shutdown al Alco S3 ?

[IAFarmer]

Those old buggers had a "ripcord" that you had to yank for the EFCO, and it is quite the pain to reset.  

[BigJim]

Boy! You two know nothing about how it was done in real life! Keep dreaming!

Isolate and hit the shutdown button (fuel shut off). Just that simple. Then knock your switches down.

[SD70Dude]

ALCO operator's manual for 539-engined locomotives:

http://www.schenectadyhistory.org/railroads/manuals/tp107a/index.html#engine

Starting instructions:

http://www.schenectadyhistory.org/railroads/manuals/tp107a/16-100.jpg

Stopping instructions:

http://www.schenectadyhistory.org/railroads/manuals/tp107a/17-100.jpg

Looks like you're supposed to shut off the fuel pump. 

[Overmod]

On a diesel engine with mechanical injection, the best way is likely to trim the engine governor so it produces "insufficient fuel to keep the engine running"; the engine will then stall with the injectors reasonably primed.  You occasionally hear an 'approximation' of this on Alcos with worn governors; the engine slows down, hesitates, almost stops running, then hammers back up to fast idle.  Problem here is that it involves going back to the engine at quitting time and knowing what to reach in and push, as opposed to just cutting off the fuel flow and being done with it.

You must be VERY careful to bar the engine over to check for hydraulic lock, something that is less likely if you just cut fuel flow.  That might be a reason you were told just to cut the pump 

Do you not have the priming routine for one of these engines?  Ask on RyPN and you should reasonably quickly get advice on all things 539.  A number of sources recommend (as would I) installing a prelubing system, which brings the lube-oil pressure up to a safe level before the engine starts to turn or fire.  I suspect that the fuel-pump pressure (which can be up to 45psi) will aid in priming the injection system relatively quickly even if one or more lines have bled down with the engine stopped...

At least technically, you could shut the engine off by blanking off the airflow.  This presumes there are no air leaks between the place you "block" the airflow and the induction ports in the head; there will also be some gargling and smoking as the governor will overfuel the engine as it begins to run out of effective combustion.

[Pat Masterson]

I was told you shut down the engine by turning off the fuel pump. That would seem to "dry" out the injectors, and make it hard to restart. Is there a better way?