embodiment except for a part of the configuration the elements of the fifth embodiment that are substantially the same as those of the first embodiment are denoted by the same reference characters while the different elements will mainly be described an air flow sensor 52 in an intake pipe 2 has an intake air temperature sensor 59 that detects the temperature of intake air the intake air temperature sensor 59 is formed as a unit in the air flow sensor 52 a detection signal from the intake air sensor 59 is input to an ecu 51 d so that the intake air temperature is available to the ecu 51 d the ecu 51 d performs control substantially the same as that by the ecu 51 according to the first embodiment and the intake temperature sensor 59 is substituted for the temperature sensor 56 of the first embodiment more specifically immediately after the ignition key is turned u201c off u201d the fuel tank 11 is approximately at the ambient temperature while the intake pipe 2 provided in the engine room is at a high temperature then the temperature of the intake pipe 2 converges toward to the ambient temperature after a sufficient period of time therefore after the elapse of a prescribed time period after the ignition key is turned u201c off u201d the temperature detected by the intake temperature sensor 59 is considered substantially equal to the temperature of the fuel.