Help please!
 

Ok so I am going to be piecing together a system for my 1996 7.3 powerstroke. I have a list of parts that I got from another person who built his own. Can someone please explain the return lines to the tanks?! Why is fuel being pumped back to the tanks after it goes through the motor? Please help clear this up

Here's what I was going to try and follow for my install. Let me know what you think and if you have any suggestions! Vegetable oil, SVO, WVO Conversion on my 1995 Dodge Cummins 4x4 Diesel Truck without making biodiesel.

that link was a little much to read during lunch. but as far as the fuel system; that's what happens to the fuel that the engine does not need. the regulator dumps excess fuel back to the tank. this keeps fuel flowing and lubricating the pump so it does not dead head and over heat, since it is always pumping.

Ok that helps to kind of clear things up.