BOSCH Electric Fuel Pumps: Operation

Fuel pumps are actuated by relays when ignition switch is in "Start" or "Run" position, and are protected from circuit overload by fuses and/or fusible links. Fuel is circulated through pump rotor and brushes to the fuel outlet. Pumps are not serviceable and should be replaced when not operating properly. For fuel pump test procedures, see appropriate Fuel Injection article in this section.