PURPOSE: To provide an apparatus for stopping fuel supply when the vehicle speed is higher than a prescribed value, which is enabled to prevent overspeed rotation of an engine in a reliable manner, by making a judgement from an engine-speed signal and an engine-load signal that the vehicle speed is higher than the prescribed value when some trouble is caused with a vehicle-speed signal.

CONSTITUTION: A vehicle-speed signal Sv is detected from the output of a vehicle-speed sensor 10 at a counter C12 of a fuel supply controlling means 25, and the signal SV is compared with a reference voltage V2 at a comparator CP2. In case that Sv is higher than V2, output of an injection quantity signal Tp from an injection quantity calculating circuit 21 is stopped by applying a signal to a fuel stop circuit 22 via an OR-circuit O1. In such an apparatus, there are provided comparators CP3, CP4 and CP5 for comparing a load signal L obtained through integration 24 of the injection quantity signal Tp, vehicle-speed signal Sv and engine-speed signal SN with respective reference voltages V3, V4 and V5. In case that all of the outputs of these comparators CP3, CP4, CP5 are H-level, that is, when some trouble is caused with the vehicle-speed sensor 10, fuel supply is stopped by producing a signal via an AND-circuit A2 and the OR-circuit O1.