PURPOSE: To advance the angle of fuel injection timing only at the time of deceleration, by arranging such that a negative pressure is introduced via a negative pressure delaying means into the negative pressure chamber of adjusting valve adapted to advance the angle of roller ring.

CONSTITUTION: A roller ring 3 having its advance angle controlled by a hydraulic timer 6 is coupled to an adjusting valve 10 adapted to advance its angle by a negative pressure exserted to a negative pressure chamber 10A. When an engine is decelerated, a negative pressure is transmitted from a negative pressure source 11 to a negative pressure chamber 13A wherein the negative pressure pulls a diaphragm 13B to open a port 12B in opposition against a spring 13E for thereby introducing the negative pressure into the negative pressure chamber 10A.