Fuel Pump Control
When ignition is turned on, EEC power relay is energized (contacts closed). Power is provided to fuel pump relay and to timing device in ECA. Fuel pump receives power through fuel pump relay contacts. If ignition switch is not turned to start position, timing device in ECA will open ground circuit after approximately 1 second.
Opening ground circuit de-energizes fuel pump relay (contacts opened) and de-energizes fuel pump. This function allows pressurization of fuel system. When ignition switch is turned to start position, ECA operates fuel pump relay to provide fuel for starting engine while cranking.