Could be several causes of the flames out the stack.
Asuming that the facility includes both a shop and a service track, injectors are normally changed out in a shop.
Dave H.
Dave H. Painted side goes up. My website : wnbranch.com
Andy Sperandeo MODEL RAILROADER Magazine
Might be many reasons for the flames out the stack. Turbo delay, that is not enough air to completly burn all flamables inside the engine some gets sweeped out with the exhaust. Bad fuel/air mix settings, roughly the same problem as the turbo delay although less temporary and could have flames constantly spewing out.
Last thing can be hard to adjust sometimes, with the engine cold it ignites all well and dandy, however once out and running it has the mentioned problem. Also worn adjustment parts and other similar problems could ofc cause the problem, and all this amounts to nothing since the minute amount of fuel wasted is not even enough to have the EPA or to not pass the green engine test thingy, constanty burning fuel is actually burning cleaner then if it was burnt inside the engine via compression and explosion.
Might even be so that they have some sort of trigger inserting fuel and igniting it to make the enviromental impact lower ... would work. Unburnt fuel would get caught in it and burn and the minute amount to keep it going would probably not be a huge expense ...
Well that's just theory.
Greetings Hans from Sweden