Well, the first reason is MSTS bin patch
Some locomotives don't support and don't work properly with MSTSbin installed.
Solution 1:
remove the patch
Solution 2:
edit loco .eng file like this:
Код:
change "MonitoringDeviceAppliesCutsPower" from 0 to 1
and loco will be fine, of course you'll still have to use 'Z' to go.