(thank you so much to everyone for your help!)
MajorAlvega, I already found and stole your code :) thank you! I have it working in ev3dev, but the next challenge is the range on the Irlink (not so great) and also the sensor needs to point directly at my train. I also found that as soon as the train goes out of range it stops. I'm not sure yet if that's just how the code is written and there's a way to just have it start and keep going, then use something else to stop it (like another sensor when the train reaches a certain spot). I notice that with the regular remote that comes with the train I can start up the train and walk away holding the remote and it keeps going, so I would think there should be a way to do it. I also posted a question on Xander's site so I'll let you know what he says too.
thanks everyone
Ian