I'm begging now I've had 33 people look at my post but not one answer. Where can I find how to fully operate my steam trains in cab mode on Tranz Classics 12&3 I have a few locos that will go for a bit and then the steam chest pressure drops and they stop.
If it is TC3 then it might be the enginespec. From TC3 onwards, a completely new enginespec, smoke and sound system was introduced which meant that most older locos required editing.