Abstract: An abnormality detecting apparatus for use in a fuel-transpiration preventing mechanism can eliminate effects of changes in operating conditions and variations in equipment to increase the accuracy of abnormality detection. Fuel gas generated in a fuel tank and then absorbed by an absorbing material accommodated in a canister is discharged to an intake pipe by opening and closing a purge control valve. A change in pressure at a negative-pressure holding time after introduction of a negative pressure to the fuel-transpiration preventing mechanism and a change in pressure at an atmosphere-air introduction time after the negative-pressure holding time are calculated and the changes in pressure are used as a basis for determining the existence of an abnormality. As a result, effects of changes in operating conditions and effects of variations in purge control valves and canister closing valves can be eliminated, thus allowing the detection accuracy to be improved.

Abstract: An electric control apparatus for a fuel injection pump comprises a fuel flow sensor for detecting the net quantity of fuel supplied to the fuel injection pump, operating condition sensors for detecting operating condition parameters of an engine, a servo device for driving a fuel injection quantity controlling element of the fuel injection pump which controls the fuel injection quantity of the fuel injection pump, and an electric control circuit for receiving detection signals from the fuel flow sensor and the operating condition sensors, computing the actual fuel injection quantity and the desired fuel injection quantity, and determining an error between the computed actual fuel injection quantity and desired fuel injection quantity to drive the fuel injection quantity controlling element of the fuel injection pump through the servo device in accordance with an error representing signal, thereby controlling the actual fuel injection quantity at the desired fuel injection quantity.