I recently bought the "American Classics" add-on from JustTrains. It's very old, but it has some NYC rolling stock that isn't available in any other form. There are J3 "Hudson" steam locos that work just fine, and then a few different EMD diesel locos (E7, F3, F7, FP3 etc). All these have one thing in common, and that is that they won't go faster than about 0.5 mph. It doesen't matter if it's just an engine or a full trainset, no difference at all. The same cars are fine with the steam locos, so the issue doesen't seem to be there. If I get the thing up to the full 0.6 mph, it keeps rolling a bit with the power off, so the it isn't a friction/brake problem either. No wheelslip.
I'm not that good with eng files, but maybe someone else can find what's wrong with them? I changed the "maxpower" value from kN to kW as it is in all other locos I have, but it made no difference.
Line 18 Damping ( 1e6N/m 1e6N/m )
Should be Damping ( 1e6N/m/s 1e6N/m/s )
Compared your ENG file to another TA E7 ENG in my Trainset. Only significant difference is above.
Opened OR and ran My ENG. Ran smoothly got up to 50mph before exiting yard. Did notice that Engine brakes were set at 100% so I had to release bot Engine and Train Brakes to move.
I think it may have been down to the faulty "kN" instead of "kW" after all. At first it didn't seem to make a difference, but it turned out my changes hadn't saved for whatever reason. On a second attempt it seems to accelerate properly up to at least 80mph.