Feeding a Carbureted Engine with an EFI Fuel Pump

It is becoming more and more common for people to use an in-tank electric pump to feed a carbureted engine.  Many new engines simply do not have the provisions to use a mechanical fuel pump.  Sometimes there is no room to have a mechanical fuel pump in the engine compartment.  Others simply want to clean up the look under the hood and do so by removing the mechanical fuel pump.

Any of our in-tank pumps can feed a carbureted engine provided that a bypass regulator is used.  Because an EFI fuel pump can produce a large amount of flow, a bypass regulator is necessary in order to return the excess fuel back to the fuel tank.  When shopping for a bypass regulator make sure that you buy one that is specific for carbureted applications.  This is because most carburetors only require around 6 psi to operate.  Typical EFI bypass regulators run between 40-80 psi while most carbureted bypass regulators are adjustable from 4-10 psi.  Keep in mind that since the pressure requirements of a carbureted application is lower that an EFI application the flow rate of your pump will be higher.  This means that the fuel pump is capable of supporting higher horsepower.  For most applications our TBI or 2 series fuel pumps provide enough flow for a carbureted engine.  

The diagram below outlines how the fuel lines can be ran using a bypass regulator on a carbureted application.  Please note that it is important to have a large return line so no back pressure is created.

Regulator Part # EDL-174053

Fuel Line Routing for EFI pump when using a Carb