Factory fuel injection 5.2 magnum using external electric fuel pump ?

[rustytoolss]

Is it possible to do Factory 5.2 magnum fuel injection just using an external electric fuel pump ? Would it cost more ? How much PSI does the 5.2 magnum system need ?

 

[Stephen Mulkey]

I don't know too much about the ins and outs of fuel injection but i I googled the fuel pressure of a 5.2 Durango and it said 44-55 psi with the engine idling, no load. 5.9 was the same. Also seem to me the injection shouldn't care if the pump was factory or aftermarket.

 

[rbkt65]

my buddy uses a ford frame mounted pump, off an f150/full size bronco, on his 37 chrysler. it has a 5.2 fi magnum in it. i think he had to regulate it down to factory specs, but i can ask him if you would like.

 

[67Dart273]

My old ranger, batch fired V6, had a low pressure pump in each tank and a high pressure pump on the frame. I see no reason, if properly done, "why not." My own Dart had Holley TBI EFI, and I used an external pump. I don't intend to go to an in-tank pump if I upgrade it to port injection.

"It might be" a great idea to use a hi volume, low pressure pump to drive the main pump

 

[jos51700]

The return line is a consideration. Some were internal in the pump, some had a return line from the rail.

 

[pishta]

Go head. The regulator will get it down to what it needs to be at. Everything over 55 psi gets dumped back into the return. IIRC the old TBI's from Ford were only 15 psi from a mechanical pump? Not sure how they would start up, maybe took a few revolutions to build pressure.

 

[jbc426]

Is it possible to do Factory 5.2 magnum fuel injection just using an external electric fuel pump ? Would it cost more ? How much PSI does the 5.2 magnum system need ?

I run an in tank pump to a front mounted surge tank with an internal pump. This set-up removes any air from the system that may be sucked up when the tank is down to the last few gallons so it won't get passed to the injectors.

Both pumps are powered by the factory fuel pump relay circuit They run for about a second before cranking when the key is turned to the run position. My Start 1 and Start 2 12V are spliced together.

 

[rbkt65]

just talked to my buddy. the motor in 37 chrysler is a 93 with pressure reg mounted on fuel rail. ford pump has approx 47 psi. all psi over what stock magnum needs is returned to tank via a homemade return line to fit car. his 49 plymouth has a 98 magnum in it and he uses a grand cherokee tank with pump module single line regulator. regulator returns excess to tank. i am using a dakota tank w/93 d250 fuel pump for my 87 truck project and son is using 1996 dakota tank and pump on his crewcab.

 

[67Dart273]

Make darn sure the return is large enough. It should be as large as the suction tube

 

[rbkt65]

i think the supply is 3/8 and return is 5/16 stock fuel line on truck.

 

[diymirage]

i think the supply is 3/8 and return is 5/16 stock fuel line on truck.

thats what i intend to run on my duster (carburated though)

 

[jbc426]

i think the supply is 3/8 and return is 5/16 stock fuel line on truck.

That is correct. I removed the 5/16" return tube and installed a 3/8" return tube in the sending unit using silver solder to seal it. I had to go to a welding supply store to source the real silver solder.