Diesel engine for dimethyl ether

A reduced idling or power consumption of the feed pump drive motor during light load and the supply pump driving noise. The A dimethyl ether 5 in the diesel engine 1, fuel, a supply pump 8 for supplying the high-pressure pump 4 on the engine side through a feed pipe 7 to the fuel of the fuel tank 6 provided in the fuel tank 6, the calculates a vapor pressure from a fuel temperature in the fuel passage portion 13 of the high-pressure pump 4, sets a margin pressure range for the vapor pressure of the engine operating conditions, the pressure of the fuel in the fuel passage portion 13 of the high-pressure pump 4 is, and a control unit 14 for controlling the supply pump 8 so that the target pressure plus the margin pressure to the vapor pressure. .FIELD 1