robyw1

Dan I don't think your method will work. To me it seems the return of fuel into the inlet will kill the pumps ability to pick up the fuel from the tank. Take the time and make a return route to your fuel tank.

Roby

articfriends

iTrader: (1)

Robyw1-it seems like you would be correct but the t between the inlet to the pump and tank method is how a stock502/454 mpi recircs its fuel from fuel cooler/regulator from mercruiser,it is considered a full flow regulator,you supply unrestricted fuel to the efi rail (or in his case the carb) and the extra is bled off thru a regulator. It has to be bled back somwhere before the pump or the regulator would be rendered ineffective. Procharger also has you do it this way and it works. Even if i wanted to return my fuel to my fuel tank on my boat there were no extra bungs on the tank,i could have plumbed it to the vent line at the front of tank but you would stand a chance of pumping gas out the vent overboard.Smitty

tomcat

sutphen30: If you go back to the tank and there is a reasonable amount of fuel in it, it's a big heat sink on its own. Same as in cars. Aeromotive shows doing it this way. They also say if the vehicle is going to be idling a lot, that their little box that varies pump voltage should be used.

On the Merc MPI system the two wires that go to the VST electric pump are not positive and negative; they are positive and less positive. the ECU varies the voltage across these two wires to change pump speed according to demand. Neat idea, easier on equipment, less return fuel needing to be handled.