Accumulation type fuel injection system

An accumulation type fuel injection system (1) of a diesel engine (2) calculates a dimensionless interval (I0) by dividing an injection interval (I) between a pilot injection and a main injection by a cycle (T) of pressure pulsation in an injection correcting operation for correcting the main injection. The fuel injection system (1) calculates correcting values corresponding to the dimensionless interval (I0) from correction maps and calculates final main injection quantity (QM') and timing (tM') by adding the correcting values (CQ, Ct) to main injection quantity (QM) and timing (tM) calculated based on operating conditions of the engine (2).