Method for operating a fuel system for a LPG engine

An operating process for a liquefied petroleum gas (LPG) engine having an electrically-driven closing valve (4) and an electrically operated heater for the gas comprises producing a signal to switch on the heater on starting the engine, determining the heating requirement and, from this, obtaining a delay time before opening the valve : An independent claim is also included for a process as above in which a closing signal is produced at engine switch-off.