Upgrades To Big Blue For Overlanding?

[Gary Lewis]

Gary, problem is the way the fuel system was plumbed for the 1985.5-1989 trucks. The in-tank pumps deliver fuel to the reservoir/tank selector assembly on the frame, this is where the high pressure pump picks up fuel from. Excess fuel from the tank selected is returned to that tank along with the return fuel from the engine. You can either use what Ford designed, or redesign it the way you want it. If I wanted to do away with the frame pump and reservoir, I would get a pair of Chrysler turbo or V6 pumps and install them on the 1985 pump/sender units, these are 75-80 or more psi capable pumps, then use your 6 port valve, provided it can handle the pressure, to switch tanks. The problem you will have, just as the present system does, will be starving the pumps, especially the front tank, on hard acceleration, braking and inclines when low on fuel.

Ford used the system on the early models so the high pressure pump would always have fuel, Chrysler uses a cute cup with the return acting as a jet pump to keep it full until the tank is pretty damn empty. Later Fords do the same with the pump module, it serves as a suction reservoir. FWIW, the high pressure pumps do not like being run dry.

Let me see if I understand - I shouldn't use the 6-port valve as there's no reservoir to keep the high-pressure pump supplied. Right?

Said another way, just to check we are on the same page, the in-tank pumps that I have are fine, but I need a reservoir to supply fuel in all conditions to the high-pressure pump and the 6-port valve doesn't do that.

So, if I run the pumps I have and Reservoir/Tank Selector Valve F1TZ 9B263-B I should be good? That way I'm using what Ford designed, although I'm not sure what in-tank pump they used as I can't find a part number on the pump by itself, just the pump/sending unit combo. So, I'd like to use the sending units and pumps I have, which are right for a carb'd 460.

[85lebaront2]

Let me see if I understand - I shouldn't use the 6-port valve as there's no reservoir to keep the high-pressure pump supplied. Right?

Said another way, just to check we are on the same page, the in-tank pumps that I have are fine, but I need a reservoir to supply fuel in all conditions to the high-pressure pump and the 6-port valve doesn't do that.

So, if I run the pumps I have and Reservoir/Tank Selector Valve F1TZ 9B263-B I should be good? That way I'm using what Ford designed, although I'm not sure what in-tank pump they used as I can't find a part number on the pump by itself, just the pump/sending unit combo. So, I'd like to use the sending units and pumps I have, which are right for a carb'd 460.

Deadhead one or the other and check the pressure, I am not sure what the pressure for the LP in-tank pumps is and AllData doesn't give me that, just the main pressure.

[Gary Lewis]

Deadhead one or the other and check the pressure, I am not sure what the pressure for the LP in-tank pumps is and AllData doesn't give me that, just the main pressure.

That's the problem - I don't know what it should be, so wouldn't know if it is correct or not. But, isn't the real question whether those pumps will trigger the valve to switch?

They supply enough fuel to run the engine, even at full chat. And the high-pressure pump will circulate fuel to the regulator and back to the reservoir, so if the pumps provide enough pressure to switch the valve wouldn't that be all that is needed?

I'll continue to look for the right in-tank pumps for an EFI setup, but so far all I've found is the whole sending unit/pump combo. And since I have both new sending units and new pumps for the carb'd version I'd like to minimize cost and use them if they'll work.

[85lebaront2]

That's the problem - I don't know what it should be, so wouldn't know if it is correct or not. But, isn't the real question whether those pumps will trigger the valve to switch?

They supply enough fuel to run the engine, even at full chat. And the high-pressure pump will circulate fuel to the regulator and back to the reservoir, so if the pumps provide enough pressure to switch the valve wouldn't that be all that is needed?

I'll continue to look for the right in-tank pumps for an EFI setup, but so far all I've found is the whole sending unit/pump combo. And since I have both new sending units and new pumps for the carb'd version I'd like to minimize cost and use them if they'll work.

One thing you may run into, I seem to remember seeing a 1989 that had the fuel lines coming in to the rail near the front of the engine due to the location of the pump and filter on the frame rail.

[Gary Lewis]

One thing you may run into, I seem to remember seeing a 1989 that had the fuel lines coming in to the rail near the front of the engine due to the location of the pump and filter on the frame rail.

You are saying that the lineup of "stuff" on the frame may bring the filter so far to the front that the lines can't go up the back of the tranny like on Huck, as shown below. Right?

If so, perhaps I can start the lineup further to the rear, meaning run the lines from the front tank rearward rather than forward. I'll have to look to see what's on the inside of Big Blue's frame now, but not much other than wiring that I remember.

And, so far no luck on the pump part number for the in-tank pumps. Ford didn't sell them other than as part of the whole sending unit assembly, so no part number to cross-reference. LMC doesn't tell, but I'm checking other sources. Perhaps Delphi?

[85lebaront2]

You are saying that the lineup of "stuff" on the frame may bring the filter so far to the front that the lines can't go up the back of the tranny like on Huck, as shown below. Right?

If so, perhaps I can start the lineup further to the rear, meaning run the lines from the front tank rearward rather than forward. I'll have to look to see what's on the inside of Big Blue's frame now, but not much other than wiring that I remember.

And, so far no luck on the pump part number for the in-tank pumps. Ford didn't sell them other than as part of the whole sending unit assembly, so no part number to cross-reference. LMC doesn't tell, but I'm checking other sources. Perhaps Delphi?

Ok, did some digging around, best I could find is the in-tank pumps are probably 9-10 psi which would probably be what you have currently since you have to drop it down for the carburetor. Location of the equipment from what I remember should be about where I circled on your picture. If you move it back about where the transmission cross member sits everything might fit and work. On the factory setup on Darth the 6 port tank selector valve was between the front end of the front tank and the frame.

[Gary Lewis]

You are saying that the lineup of "stuff" on the frame may bring the filter so far to the front that the lines can't go up the back of the tranny like on Huck, as shown below. Right?

If so, perhaps I can start the lineup further to the rear, meaning run the lines from the front tank rearward rather than forward. I'll have to look to see what's on the inside of Big Blue's frame now, but not much other than wiring that I remember.

And, so far no luck on the pump part number for the in-tank pumps. Ford didn't sell them other than as part of the whole sending unit assembly, so no part number to cross-reference. LMC doesn't tell, but I'm checking other sources. Perhaps Delphi?

Bill - Thanks. That location should work fine since I should be able to route the lines you see to the front instead of the rear.

However, I think I may have an answer to my pump question: Here's the summarized info from Delphi's catalog:

• High-pressure pump for 1986 5.0L w/EFI: FD0029, which flows 28 gph, works at 44 psi, and has a relief at 90 psi

• 1986 5.0L EFI in-tank pump: FE0484, which flows 30 gph, works at 2 psi, and has a 6 psi relief

• 1985 460 carb in-tank pump: FE0127, which flows 24 gph, works at 36 psi, and has a 65 psi relief

I have two brand new FE0127's, and that would seem to be a no-go. However, here's the 1987 F250 460 page from Dephi, and it shows the FE0127 used for the aft-axle plastic tank and the FE0484 used for the aft-axle steel tank. HELP!

[85lebaront2]

Bill - Thanks. That location should work fine since I should be able to route the lines you see to the front instead of the rear.

However, I think I may have an answer to my pump question: Here's the summarized info from Delphi's catalog:

• High-pressure pump for 1986 5.0L w/EFI: FD0029, which flows 28 gph, works at 44 psi, and has a relief at 90 psi

• 1986 5.0L EFI in-tank pump: FE0484, which flows 30 gph, works at 2 psi, and has a 6 psi relief

• 1985 460 carb in-tank pump: FE0127, which flows 24 gph, works at 36 psi, and has a 65 psi relief

I have two brand new FE0127's, and that would seem to be a no-go. However, here's the 1987 F250 460 page from Dephi, and it shows the FE0127 used for the aft-axle plastic tank and the FE0484 used for the aft-axle steel tank. HELP!

You are running into what I did on Darth originally, metal or plastic tanks, damn nightmare. Let me do some digging later. I believe the FE0127 may be either wrong or the wrong specs.

[PetesPonies]

Bill - Thanks. That location should work fine since I should be able to route the lines you see to the front instead of the rear.

However, I think I may have an answer to my pump question: Here's the summarized info from Delphi's catalog:

• High-pressure pump for 1986 5.0L w/EFI: FD0029, which flows 28 gph, works at 44 psi, and has a relief at 90 psi

• 1986 5.0L EFI in-tank pump: FE0484, which flows 30 gph, works at 2 psi, and has a 6 psi relief

• 1985 460 carb in-tank pump: FE0127, which flows 24 gph, works at 36 psi, and has a 65 psi relief

I have two brand new FE0127's, and that would seem to be a no-go. However, here's the 1987 F250 460 page from Dephi, and it shows the FE0127 used for the aft-axle plastic tank and the FE0484 used for the aft-axle steel tank. HELP!

Gary, you listed pumps pressures are spot on for the first two. Most any SEFI system operates about 40-45 PSI. TB systems operate much lower. But what I don't understand is the pressure for the carburetor system. Anything over, about, 5-7psi will lift the needle. I know it can be regulated down, but I can't understand why that lists such a high pressure for a carb. The typical low pressure in tank pump works pretty good for a carbureted engine.

[85lebaront2]

You are running into what I did on Darth originally, metal or plastic tanks, damn nightmare. Let me do some digging later. I believe the FE0127 may be either wrong or the wrong specs.

Ok, found some information, using 1989 as a MY I found:

Precise 402P2485 pump only, rear steel tank low pressure says 6 psi

Precise 402P2487 pump only, for 17 or 19 gal center tank says 7 psi

Delphi FE0484 pump only, for steel rear tank says 2 psi

Delphi FE0070 pump only, for 17 or 19 gal center tank says 36 psi

Good luck with it, I would say if your in-tank pumps produce around 6-12 psi they should operate the switching valve without a problem.

FWIW, the carbureted in-tank pumps are essentially centrifugal pumps, the EFI LP pumps I believe are gearotor style pumps (miniature oil pumps).