Fuel Pump

An electric fuel pump is used to provide fuel pressure of about 60-80 psi (4.1-5.5 kg/cm² ). An accumulator and check valve operate to maintain pressure in the system when the engine is not running, to aid in starting. The fuel pump is controlled by a relay to prevent it from continuing to operate if the engine stalls. It can be wired in several ways, the most common being through a switch on the air flow sensor or through a coil energized by the ignition system. When testing the system, the safety relay must be bypassed.