The invention relates to an arrangement and method for a combustion engine with direct injection and in particular to switching between two types of fuel. A high-pressure pump (10) is connected to a combustion engine and the high-pressure rail for the direct injection of a fuel. At least two fuel storages (21,27) containing petrol and liquefied gas are present. The arrangement allows for switching from one fuel to another. Switching occurs by purging a fuel from the high-pressure pump (10) and the fuel supply line connected thereto by temporarily collecting the fuel in a purge unit (28). The purge unit (28) is arranged for purging the high-pressure pump (10), thus f orcing out the prevailing fuel and replacing it with the new fuel.