On multi-engine planes my throttle will sometimes only control one of the engines. Does anyone know how to get the throttle to control all of the engines again ?
Hold down your E key while hitting 1-2-3-4 in quick succession.
May I suggest if you don't have a joystick to get one. It will make your flights much more enjoyable.
In FSUIPC there is a checkbox setting for a single throttle to command all engines.