Control apparatus for a vehicle engine electric fuel pump

A control apparatus for an electric fuel pump of a vehicle with an internal combustion engine, comprising:

• a battery power source;
• motor means for operating said fuel pump in response to power from said power source;
• resistor means provided between said power source and said motor means;
• switch means connected between said power source and said motor means in parallel with said resistor means;
• engine condition detecting means for detecting an engine condition value related to a required fuel quantity of said engine;
• voltage detecting means for detecting a voltage condition value of said power source;
• switch control means having at least one reference value set beforehand in correspondence to said engine condition value, said switch control means controlling said switch means by comparing said engine condition value with said reference value such that when a relationship between said engine condition value and said reference value represents a condition in which said required fuel quantity corresponding to said engine condition value is larger than a reference required fuel quantity corresponding to said reference value, said switch means is closed, and when said relationship represents a condition in which said required fuel quantity corresponding to said engine condition value is equal to or less that said reference required fuel quantity, said switch means is opened;
• and
• reference value changing means for changing, when said voltage condition of said power source is lower than a predetermined setting value, said reference value in said switch control means in a direction in which said engine condition value changes with a decrease in said required fuel quantity.