Fuel Pump: Description and Operation
PURPOSE AND OPERATIONFuel pump make / type is an AC Delco-high pressure electric pump. It delivers a high volume of fuel to the injector rail to provide a constant supply of fuel.
The electric fuel pump is a self priming WET pump. The motor is immersed in the fuel within the tank.
Fuel is supplied to the engine via the tank-mounted electric pump. The pump is capable of delivering more fuel volume and pressure than required by the engine. Most of the fuel circulates through the fuel rail and is returned to the fuel tank. This constant supply of relatively cool fuel through the system helps prevent vapor lock.
A non-return valve in the pump prevents fuel from the injector supply pipe from draining back into the tank with the key OFF. The advantage of mounting the pump in the fuel tank is that the pump armature and bearing are cooled by the surrounding fuel. The tank also helps isolate any noise produced by pump operation.