To provide an electronic control accumulation fuel injection system for diesel engine capable of inhibiting an engine vibration of a whole V type 6-cylinder diesel engine 10 and also inhibiting a mechanical engine inherent vibration which every cylinder has.

When an unloading state of a diesel engine 10 is detected, a rotation speed variation every in explosion stroke of the respective cylinder is detected. An average value of the rotation speed variation of all cylinders is compared with a detection value of the rotation speed variation of every cylinder. A FCCB study control for compensating a fuel injection amount to the respective cylinders of the diesel engine 10 is carried out so as to flatten the rotation speed variation every in the explosion stroke of the respective cylinders based on this comparison result. Thereafter, an injection amount weight is added to a fuel injection amount to a specific cylinder being a vibration source so as to reduce a mechanical inherent vibration which every cylinder has. Thereby, not only an engine vibration of the whole engine is inhibited but also a mechanical engine inherent vibration which every cylinder has can be inhibited.