PURPOSE: To prevent a vapor lock by providing a temperature detecting sensor near to a place where a fuel injection valve is attached to perform an incremental compensation of fuel injection corresponding to a detected temperature.

CONSTITUTION: A temperature detection sensor, for example a thermister (NTC), or a positive characteristic thermister (PTC), is provided near to a place where a fuel injection valve 2 of an electronic fuel injection unit attached engine 1 is fixed. And an injection fuel amount incremental compensation is performed in accordance with an electric resistance variation of the sensor 3 which corresponds to a detected temperature. A temperature TA or about is a temperature where a vapour lock occurs, and by increasing a fuel incremental injection amount q when T is greater than the TA, a vapour lock can be prevented.