Fuel Filter Lines

[BCMTNKJ]

On a 2002 Jeep 3.7l. Can some explain why there is two lines going from the lower fuel pump, passing out the upper module into the fuel filter where it goes to one line coming out of the filter? What is the purpose of two lines into the filter?

Edit- Found the detail in the service manual. Looks like it’s to do with the pressure regulator

 

[JeepJeepster]

Its both a filter and a regulator. I assume that second line is the return line.

On some vehicles, like my 94 ZJ, the regulator is on the fuel rail. So the fuel goes into the fuel rail, then the extra fuel goes back to the tank.