The most reliable way to start my Legacy engines (New York Central S2 Electric motor, Ten-Wheeler steam engines, LIRR Camelback) conventionally with a Z-4000 is to apply 13 volts, wait a few seconds, then a short press of the direction button. That gets the engines moving every time - with sounds, and it is normal operating procedure on my railroad. I don't get reliable starts by retarding the throttle to exit from neutral and move forward.
MELGAR