To maintain acceleration properties and exhaust characteristics in an excellent state and to suppress the generation of diesel knock noise.

Fuel injection control during acceleration of a diesel engine having a turbo charger is executed. Based on the number of revolutions of an engine and the opening of an accelerator, a fuel injection amount is computed. Based on a change amount Δθ of an accelerator opening θ, it is decided at steps 200-202 whether or not an engine is at an acceleration starting period. When it is at an acceleration starting period, the starting timing of fuel injection is transferred to the angle of lag and an initial value A is set at a prestroke value A at a step 206 to increase a fuel injection pressure. Thereafter, while a counter CACC counts down a given time BO, the prestroke valve A is gradually damped at steps 208-214.