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Electronic fuel injection 6 way valve

Bulldoglover

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May 1, 2011
Messages
159
Can somebody on here explain how the plumbing works on a EFI system utilizing a 6 way valve, with twin tanks on a 74 Bronco? Also what does the module do and what is the plug in on top of the module do, I assume it's for settings or diagnostic. Thanks for any responses. I've had numerous Ebs with dual tank setups with the 3 way valve, but a member explained that the EFI is higher pressure and you cannot use the 3 way anymore, lastly One member suggested I convert my aux tank to transfer tank. I assume I get a rail mounted 12 volt fuel pump with a dash switch and pump fuel to the main tank when needed. How does that effect my 6 way valve now.. I know that's a lot of questions, but I want to get it all done the correct way no need in reinventing the wheel, if you guys have been there done that, thanks
 

DirtDonk

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I've heard that some 6-way valves are not up to the task as well. Which model/brand did you get?
Which module are you talking about?

Which EFI setup are you running?
Are there fuel pumps in each tank? Or are you using a single pump on the frame?

Paul
 

DirtDonk

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When you said "module" were you talking about the valve itself? If so, that plug is for the valve to work. You need to have a switch on the dash (your gauge switch) actuate the valve so that it knows whether you want it in the AUX or MAIN positions.

When plumbed properly, the feed line lets the pump pull or push gas through the valve up to the engine. The secondary port is a return port and needs to be plumbed to a return port on the gas tank.
Each tank has it's own feed and return line then, controlled by the valve and feeding only one tank at a time.
This way when you're pulling from one tank you're not returning to another.

Most aftermarket valves are easy to distinguish between feed and return. The larger (usually 3/8") ports are for the feed and the the smaller (usually 5/16") ports are for return.

Is that what you were wondering?

Paul
 
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Bulldoglover

Bulldoglover

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Performance Fuel systems I'm using one fuel pump at present on rail and the 6 way valve the module is mounted on my fenderwell. I have pics but don't know how to post them, the 6 way is 4 in 2 out, not same as module. I'm thinking about putting a check valve in each supply line so there is no way for fuel to get pushed back to either tank if switch is wrong . I'm thinking the supplemental pump is the way to go but not sure how to plumb it. I know there is a feed line and a vent line on each tank.
 

Steve83

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Jul 16, 2003
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Read the first several posts in this thread:
http://www.supermotors.net/forums/thid-5972-how-do-i-post-pictures-sounds-and-or-videos

You still didn't say what this "module" is.

A 6-way valve has nothing to do with the EFI pressure - you should NOT have a high-pressure pump going TO the 6-way valve. It's to allow fuel to return to the tank it's coming from, which is how most EFI fuel systems work. But if you're using one of the tanks as a transfer, you don't need any valve.

There are pros & cons to each way of setting up the fuel system for 2 tanks - none is inherently "better". To help you choose, we'd need to know exactly how you plan or expect to use the truck, and what you want it to do. But I don't think ANY factory system uses a transfer tank, so keep that in mind.

Consider these:


(phone app link)



(phone app link)
 

weekend warrior

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May 4, 2018
Messages
64
Loc.
Seabeck, WA
Can somebody on here explain how the plumbing works on a EFI system utilizing a 6 way valve, with twin tanks on a 74 Bronco? Also what does the module do and what is the plug in on top of the module do, I assume it's for settings or diagnostic. Thanks for any responses. I've had numerous Ebs with dual tank setups with the 3 way valve, but a member explained that the EFI is higher pressure and you cannot use the 3 way anymore, lastly One member suggested I convert my aux tank to transfer tank. I assume I get a rail mounted 12 volt fuel pump with a dash switch and pump fuel to the main tank when needed. How does that effect my 6 way valve now.. I know that's a lot of questions, but I want to get it all done the correct way no need in reinventing the wheel, if you guys have been there done that, thanks
I have dual tanks in my 69 U-100. I'm running throttle body EFI, with a Pollak 6- port motor driven fuel tank selector valve, model 42-303. I have an in line EFI holley fuel pump for each tank. The plumbing for both supply and return is 3/8 EFI fuel line from the throttle body to the switching valve and there are connection on the valve for each tanks fuel supply and return. The kit comes with the toggle switch that is a direct replacement for the stock fuel tank selector toggle in the dash. You cannot use the original toggle for this valve because it only switches over the fuel gauge. The toggle that goes with the switching valve controls the tank selection, fuel supply and return and the fuel tank gauge sending unit.
 
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DirtDonk

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Also what does the module do and what is the plug in on top of the module do, I assume it's for settings or diagnostic.

Don't know of any modules with most EFI setups. If it's red module it might be an MSD Atomic system. Any names or designations on stuff?

Being a '74 it might also have had a Ford electronic ignition originally and someone just left the old ignition module on the wheel well. But by your description of a "plug on top" I don't recognize it.

A member explained that the EFI is higher pressure and you cannot use the 3 way anymore

I've heard that too, but not sure how it is with maybe a new valve? Maybe they're just not made for 40-100 psi, which would not be surprising.
But they also don't have a method to direct the return flow. Which is why no matter if it's manual or electric, you need 6 ports if you're going to run EFI in the normal modes with dual tanks.

One member suggested I convert my aux tank to transfer tank. I assume I get a rail mounted 12 volt fuel pump with a dash switch and pump fuel to the main tank when needed.
How does that effect my 6 way valve now.

You assume correct. When the main tank starts running low you turn on the transfer pump and simply transfer all the fuel in the auxiliary tank into the main tank where your pump can utilize the feed and return lines.
As Steve said, it effects your valve by making it completely unnecessary.

Almost no such thing as too many questions. We just need more details.

Performance Fuel systems I'm using one fuel pump at present on rail and the 6 way valve the module is mounted on my fenderwell.

Performance Fuel seems to make only accessories for fuel injection systems. Not the systems themselves. So yeah, we're still going to need more details or some good pics.

I have pics but don't know how to post them

No problem. To upload directly you need to become a contributor for 12 bucks a year. Or you can use an online image hosting site like SuperMotors where Steve83 resides.;D
You can e-mail some to me at paulb@wildhorses4x4.com or upload some to your "garage" function in your User CP area above.

the 6 way is 4 in 2 out

Not quite. It's actually 3-feeding the engine and 3 returning to the tanks.
If they're all the same size then you need to look up some sort of road map to which is which. If they are different sizes then on the side with 4, the two larger ones are "feeding from" each tank, while the two smaller ones are "returns to" the tanks.
The side with 2 ports the large one is the feed to the engine and the small one the return from the engine.
This way when you switch the valve it returns fuel to the same tank it's pulling from. If it did not, then you might be pulling fuel from one tank and returning it to an already full tank. Overloading and spilling fuel out of every available orifice.

not same as module. I'm thinking about putting a check valve in each supply line so there is no way for fuel to get pushed back to either tank if switch is wrong .

Check valves are not a bad thing. But they're usually not necessary either. Your pump should, I believe, have a built-in check valve value itself. But some have added additional ones.
The real trick is to just not hook up the plumbing wrong.

I'm thinking the supplemental pump is the way to go but not sure how to plumb it. I know there is a feed line and a vent line on each tank.

The vent lines will be different, because they're only supposed to pull vapors from the tank and store them in the charcoal canister on the passenger front frame rail. First they go to the plastic condensing tank behind the driver's left shoulder, then any liquid that condenses is allowed to feed back to the main tank via a small return line.
With EFI you need full independent feed and return lines. Different ways of doing it of course, but most try to return to the tank that's being used, while some will return to a common point, or reservoir in the feed line so that the fuel goes right back into the system and re-fed to the engine.
I like routing them to the tanks, but have not used many different setups myself yet.

Paul
 
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Bulldoglover

Bulldoglover

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Wow lots of good information Now i'm really confused, I'm going to become a contribution member so I can post photos.. Well worth the $12.. Thanks guys
 
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Bulldoglover

Bulldoglover

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May 1, 2011
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Top photo is Electronic module (Note black plug in for diagnostic)
Middle photo is electric Fuel Pump?
Bottom photo is 6 way or 4 in 2 out solinoid valve with 12 vdc power
 
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Broncobowsher

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Messages
34,835
I have run a manual selector valve with a transfer setup before. The valve selected which tank fuel came out of, but all the return went to the main tank. Benefit is you can't forget to turn the transfer pump out and burn it up, because if you run the tank dry you run out of fuel, until you switch the selector valve.
 

Broncobowsher

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What you have there is a GM throttle body EFI. Company info http://pfisys.com/store-3/#!/Ford-Parts/c/10944421/offset=0&sort=normal

That box is the ECM to run it. That connector is the diagnostic port. Treat this as if you were working on an '88 chevy half ton with a 350 in it. That is what you have, just with a little custom work done to it.

Middle is a fuel pump.

Bottom is a 6-port valve. Never seen that style before. Looks like parallel solenoids and not actual valve? Actual valve as in a motor driven selector. Solenoid selects one set of port when powered, defaults to the other ports when power is off. Does not hold position with power removed. Most of the 6-port valves are motor driven and when the power is removed the ports won't change, at least until power is put to it again to shift it the other way.
 

lars

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If you want a manual alternative, there are 6 port valves available that fit in the OEM location that meet the requirement for feed and return:

https://www.groco.net/products/valves-seacocks/fuel-valves/fv-6-port-series

I have an aircraft valve in mine because I got a bargain on it. Beautifully made but unfortunately with a price to match:

http://www.andair.co.uk/product/duplex-fuel-selector-fs2020-d2/

I've gone through 2 Pollak motorized valves, they arguably lasted almost a decade apiece, but the last one died a few weeks ago when I was on a middle of nowhere trip (overland expedition?) when losing access to the aux tank was a big deal. Manual valves for me from here on out.
 

DirtDonk

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Now i'm really confused...

Hah! I'm good at that!

I had missed the pfisys.com website. The one I found only showed accessories such as replacement fuel rails, pressure regulators and such. Maybe I just didn't drill down deep enough, or maybe it was the wrong site.

Sorry for the confusion, and thanks for becoming a contributor. Not only to help keep us up and running the way we're used to enjoying, but for posting up the pictures to help figure this out!

The fuel valve kind of looks like the bottom end of a regular motorized style to me. But a picture of the wire connector would answer that. If it's a 5 or 6 wire Weatherpack style connector, it's probably the normal valve.

Paul
 

Broncobowsher

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Paul, you were looking at the wrong site. Took a bit of digging to find the one with the same logo. Not a big company. I was a bit surprised to find anyone was still doing GM throttle body EFI conversions. They were the great thing back in the late 90's but died out in the '00s as mustang based EFI became the norm. And now we are moving on to Explorer based EFI. So it is a couple generations old. But somehow they are still in business.
 

DirtDonk

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Yeah, I checked out the one you linked to and saw all the kits. Glad you found it.
I can't fault them for still using tried-and-true tech that was, until just a couple of years ago, less expensive than just about anything else out there.
They've probably been doing it for a long time now, and now all the current press and hype is FiTech this, and Holley that. Albeit with an equally large increase in complaints about EFI teething problems!
Hmm, I wonder if the GM TBI swaps are better than the new crop?

But you're right. It's way old tech, and the Ford factory stuff is more sophisticated (GM finally took the trucks down that road in '96) and should work better. But hey, you can't argue with simplicity.
I wonder what took GM so long? They had been using SEFI on engines since the very early '80's in cars. Buick V6's were stone reliable and super efficient. Profit margin I guess.

Paul
 
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