5.0 fuel injection psi

[neverdone]

just bought a 99 merc mountaineer w/a reliable running 5.0l v8, i plan on putting the entire drivetrain from the merc into my 67 f100
this might be a dumb question but will the stock in-cab tank with hold the pressure from all the psi coming from the fuel injection system?

anyone know how much psi come from those motors?

[averagef250]

The mountaineer pump will not work in the in cab tank. You can use a frame mounted FI pump though. They operate around 45 PSI. Not sure what the line pressure has to do with the tank though.

[Dragon]

It won't harm the tank.

[neverdone]

well why i couldnt use the fuel pump in that tank?
and what i meant was will the metal of the tank hold up...because they're built to hold psi from a carbed motor, idk maybe i'm just thinking too much...

[averagef250]

There isn't any pressure in fuel tanks. The in tank pumps will not fit through the sender opening in the cab tank. That and it just makes a lot more sense to run a frame mounted pump when doing an EFI repower.

I think 99 is EEC-V control. You may want to reconsider going with that engine/transmission. You will have to know what you're doing to get that working in an old truck.

[neverdone]

haha, yea but it doesnt discourage me, if there's a will there's a way =)

i have a inline fuel pump lying in storage that i would change the fuel pump and regulator to push out enough for the fi....

[averagef250]

The regulator is on the fuel rail. Carb pumps will not make enough pressure.

[fordman]

thats right carb pumps only pump about 6-12 psi. the efi pumps are up and maybe past 45 psi like average said.

[mouse]

you can get a good fuel pump from a late 80s to 96 broncos and f-*50s, the high pressure one on the frame and it don't need the low pressure one to work, just put a fuel filter before it with two ins one for return and the other for gas in. they sit below the drivers door on the inside of the frame

[Dragon]

Rangers also had them in the same place.

[averagef250]

Unlike many out there, I actually love the idea of the in-cab tank as it solves a heck of a lot of real world problems like diesel fuel gelling or anything popping a hole in the tank. I've done plenty of EFI and diesel swaps into bumps and dents and toyed around with different fuel systems. I believe simple, available and affordable are the best ways to build anything and definitely tried the stock 87-89 frame rail pumps. At best, even with a pusher pump they are disapointing. The problem I've found with the cab tanks is long left hand corners. The fuel goes to the passenger side and uncovers the pickup tube causing the pump to suck air and lose prime. Running an 87-89 pump in an EFI swap I had constant bouts of power loss on left corners and even rough roads. I made one 500 mile trip with the EFI 300 in my 70 F-100 with the 87-89 pump and had to get under the truck several times throughout the trip, disconnect the suction side and blow into the tank filler to get fuel back down to the pump.

I've had best luck with Bosch inline pumps used in European cars through the 80's and 90's. The Bosch pumps are quiet, self prime and are very rugged. When my best friends '77 F-250 4x4 with an EFI 300 had the used Toyota EFI pump I used fail soon after installing it I got him to spring for a new Bosch pump. That was a few years and 30K miles ago and it's working great.

[averagef250]

you can get a good fuel pump from a late 80s to 96 broncos and f-*50s, the high pressure one on the frame and it don't need the low pressure one to work, just put a fuel filter before it with two ins one for return and the other for gas in. they sit below the drivers door on the inside of the frame

Just to clarify here, Ford went to ONLY high pressure pumps in the tanks in 1990. Only the trucks before that have the two and three pump systems.

Also, running the return line into the suction side of the pump is not a great idea. The return should go to the tank to get any air out of the fuel supply and to recirculate fuel to keep the pump cool. I find one of the little red rubber spray nozles off of factory EFI fuel tank returns and use it on the end of a short piece of 1/4" or 3/16" tubing soldered into the sending unit flange.

[mouse]

it may not be a real good pump but it is easy to find in the junk yard, with any in line pump you want fuel to return back to it not to the tank, it will keep the fuel flowing to the pump, that is way I mentioned that type of filter. I have a friend with a 87 bronco that I removed the in tank pump because it never worked right and it has ran perfect since

[fitzwell]

The return should go to the tank to get any air out of the fuel supply and to recirculate fuel to keep the pump cool. I find one of the little red rubber spray nozles off of factory EFI fuel tank returns and use it on the end of a short piece of 1/4" or 3/16" tubing soldered into the sending unit flange.

not to hijack....what method do you use to get the return line into the factory pickup? I'm in the process of adding a return line on my application & need to get the return plumbed into a stock mustang sending unit. Thought about soldering it, but i'm concerned about vibration at that joint. Also, what size return line do you use? Most sources i've spoken with tell me same size as the supply( which would be 3/8 in this case) I'm just thinking with a carbureted motor & electric pump, i should be able to get away with 5/16, or even 1/4???




now back to our regularly secheduled thread

[averagef250]

I find one of the little red rubber spray nozles off of factory EFI fuel tank returns and use it on the end of a short piece of 1/4" or 3/16" tubing soldered into the sending unit flange.

Ford EFI systems use a 1/4" or 5/16" return line. 1/4" is plenty adequate for a non-race fuel pump. I take the sending unit out and drill a hole in a convenient place. If you're working with a sending unit that has the rheostat mounted to the flange you will have to carefully disassemble it and remove any parts that will be damaged by a torch. Clean the parts well, slip the tube in and solder it in place. If you do not use the rubber tip nozzle on the return line you'll aerate the fuel in the tank more and the fuel return will be louder. Hope this helps.