Electric Fuel Tank Selector Valve- Troubleshoot

[B-man]

New around here..

Sold My 88 Bronco , now working on a 73' Bronco...

I was wondering if there was any way of testing the Electric Fuel Tank Selector Valve?

Reason for testing is because I cannot get the Aux tank to work on the Valve. The Main (rear tank) works fine but , when switching to Aux, the gauge works but, the Selector isn't switching..

I do not much about these Selector valves..

I have 12v of power on the hot wire coming down from the dash switch to the selector valve, when it is disconnected. When that hot wire is connected to the valve, I have 4.5v. This would be when I am on the main tank. When switched to the aux, I have 0.00. Which , with what I read , is correct?

I have installed a new ground and hot wire. 18g..

I have also notice that I have slits in both the rear and aux filler hoses . As well as the other hose/line located on the rear tank that goes back up to the filler neck. That hose is wasted.

I am in the process of ordering those. I am wondering if I should order a new Selector Valve as well? I hate just throwing parts at a problem but, I do think my Valve is toast.

So, I am hoping there is a way to test the Valve.

Sorry for the long winded post. I apologize if there's already a thread on this, I just didn't see it when searching.

 

[Viperwolf1]

What you're describing isn't stock. It sounds like you have an electric 3 port valve operated off the stock sender switch. Is that correct? The stock valve was manually operated. In this case you need to look at the way the sender switch is wired up. You want it to send 12V to the valve and send 5V to the senders.

Look at the back of the switch and you'll see 2 rows of 3 terminals. Each row acts like a separate switch.

 

[blubuckaroo]

If you have the aftermarket electric selector valve sold by some of our vendors, it is ported to the aux tank when energized, and it defaults to the main tank port when de-energized.
I believe you'll need 12 volts, not 4.5 volts.

 

[B-man]

The Manual switch for the tanks was removed I do apologize for not mentioning that.

The selector valve we have had on it, is the same switch that Tom's or Wild Horses sells. The switch has been on the truck since we received the truck over 12 years ago.

http://www.wildhorses4x4.com/product/Electric_Tank_Switching_Valve



I do have the six pin fuel switch that is shown Vipers post. But, I don't believe it is hooked up that way. I think I have the Fuel valve on the wrong pin. I have my

I had 12 volts when I didn't have the hot lead connected to the the selector valve.

Just noticed on the Wild Horses Site that they have some installation instructions..

I will have to see what is what. I am not sure how this truck was running for the years it was with this setup, because, something doesn't look right..

Thanks for the help guys. Off to research and investigate I go.

I know one thing, I don't have two fuel filters between the tanks and Selector valve. And, I didn't see any fuse links anyplace on the wires. I will be adding these.

There was one other thing I noticed. The previous owner left the manual switch that switch the fuel gauge between the tanks. On the toggle switch, one red wire that goes back to the voltage regulator? Located on the passenger side of the truck engine bay, on the fire wall. The other red wired was just dangling around the steering column, taped up.. Once again, this was the previous owner that did all this. I have just begun to see what needs to be looked at with the truck. I am wondering if I can , or should use that red wire from what I believe is the voltage regulator for the switch?


Thanks for the help guys. Off to research and investigate I go.

 

[blubuckaroo]

I saw the "must have" about the filter requirement, and ignored it. I see it as the lesser of two evils, since more than one filter with a mechanical pump is a bad idea. I figure the requirement was put in the instructions as a CYA.

 

[B-man]

We just have one filter on it now. Right by the Carb...

The whole setup was working before. I am probably overthinking it all and the possibly the valve just went bad.

 

[B-man]

Oh Boy..

So, I took off the selector valve, and it is a 6 port selector valve? Made by Pollak.

So, it isn't like the valves at Tom's or Wild Horses..

I assume I have a 6-port because I have an additional line coming from both tanks, and , one steel line off of the fuel pump that leads up and the steel lines meet , come as one and one steel line routes into the carb.


I am assuming they are return lines.

Here's the selector valve I pulled off of the truck.




And, here's the fuel lines that one side comes off of the fuel pump and connects up towards the carb..




I am assuming these are possibly return lines? Smog crap? Can it be removed so I can just run the basic selector valve.?

I really need to get a manual for this rig. I don't like being this uninformed..

Thanks for any help, info.

 

[blubuckaroo]

Wow! that's a lot of fuel line!
It looks like someone's attempt to eliminate vapor lock by adding some sort of bypass regulator and return valve system. That electric valve is made for a fuel injection application with two tanks.
I'd replace it with an electric valve with a single port, and get rid of the bypass stuff.

 

[Viperwolf1]

That fuel return is a late '72 to early '73 thing. If you're gonna rip it out at least get some pictures of everything first. This kind of info is difficult to find now.

 

[B-man]

I am just wondering how it was all hooked up originally. Those return lines or what ever had to go someplace?

I was either going to go back to the mechanical switch, or possibly purchase the valve with 3 ports.

I located the canister on the passenger side of the truck, by the fender well. Not sure what it is really doing at the moment because on the top of it, it just has two holes and what's left of some kind of materials. not rubber, I will take a pic of it tomorrow.

When I took off the fuel line today, the rear tank fuel hose was just flowing gas out, had about 7 gallons in there.. The auxillary was a fuel tank and nothing but drips came out of that hose.

I guess I am still just stumped as to why all of a sudden it just stopped working.

I wasn't planning on just ripping it all out. I am not sure If I can safely do that.. But, I am also not sure if I can find another 6-port valve for the truck.

I usually take mass pictures of work I do on the rigs.. There is definitely a lot more info around for the 88 Bronco I had.

I will take more pics after work tomorrow and will get what I can of the fuel line setup.

 

[DirtDonk]

I am just wondering how it was all hooked up originally. Those return lines or what ever had to go someplace?

Same place they go now. The original selector valve had six ports, just like the electric one does now. They've been hard to source for many years, so someone either just couldn't find one, didn't like the smell of gas when the o-rings got old, didn't want to pay the price for a new one if they did manage to locate one, or like many of us, just like the electric valves.
As said, that looks like the Ford setup near the carb. Slightly relocated, probably due to the HEI distributor taking up some of the space it originally occupied, but stock on some EB's.

I was either going to go back to the mechanical switch, or possibly purchase the valve with 3 ports.

You can do either. You can also test the electric switch on the bench with 12v to the terminal. Simply blow air through the ports on the right, and listed for air escaping the ports on the left, to see which ones work and when.

I located the canister on the passenger side of the truck, by the fender well. Not sure what it is really doing at the moment because on the top of it, it just has two holes and what's left of some kind of materials. not rubber, I will take a pic of it tomorrow.

Standard '70.5 to '75 charcoal canister.
The two large ports had tubes made of some fiberous paperlike material with wire reinforcement. Someone didn't take care of them or just decided they "didn't want no emissions crap on my truck" and ripped it off.
One large tube fed fumes up to the air cleaner housing.
One large tube just allowed ambient air into the canister to aid in purging.
The small tube went back to the condensing tank behind a panel by the driver's shoulder.

When I took off the fuel line today, the rear tank fuel hose was just flowing gas out, had about 7 gallons in there.. The auxillary was a fuel tank and nothing but drips came out of that hose.

Very normal for the main tank to siphon out on it's own like that. Not sure if the aux tank would do that as well, but perhaps it had something to do with the angle of the truck?
That or there is some sort of blockage in the lines. Which might explain why you're not getting action from that tank (if that's what's going on).

I wasn't planning on just ripping it all out. I am not sure If I can safely do that.. But, I am also not sure if I can find another 6-port valve for the truck.

They exist all over the place. The Pollock company still makes them, but most of the six-port styles I've seen are the "motorized" type, vs the more basic "solenoid type" you have.
Should be easy to find one and wire it up. Not easy to find them cheap of course, but even deals on them are out there.
It's what I installed on mine.

Good luck.

Paul

 

[B-man]

Thanks for all the info!!

 

[ransil]

I had an issue with the same valve once, it turned out to be the sending unit on the aux tank was hitting the body when the straps were tight, caused the valve not to switch.

I have it for sale, bought it 20 years ago used it for about 5, been siting in the garage since 1997

 

[B-man]

Paul,

Is something like you installed?

http://products.pollakaftermarket.c.../light-truck-6-port-motor-driven-valve/42-300

 

[DirtDonk]

That's exactly it. Mine came with the proper Weatherpack style connector/pigtail too, which I just wired per the instructions. My stock dash switch does both the gauge and the valve just like yours is/should/did.

One nice thing about the motorized style (at least in my opinion) is that once it reaches it's selected position, it no longer needs any juice to stay there. So there is no constant load on the (already finicky) dash switch, and it's already in position when the key is turned the next time.

I suppose that could be a detriment when it fails though, as it would stick in whatever position it's in and not default back to the main tank in a pinch. But that's such a distant probability that I'm not worried about it.
And besides, in an emergency the hoses can always be swapped easily to suck from the tank with the gas. Easy peasy...

Paul

 

[B-man]

Right on man. Thanks!..

This has been a fun time researching this rig and learning about it. Completely different animal than my 88 Bronco.. Night and day.

 

[ntsqd]

FWIW I would keep some form of return system in place, even with a mechanical fuel pump. Helps to eliminate vapor lock by not letting the fuel just sit in the lines anywhere in the supply system. Come summer over there in Simi you'll be glad it's there & functioning.

I'll bet that Ford part in front of the dizzy is some sort of pop-off check valve. Holds pressure up to some setting (low psi since carb'd) and then over that pressure it opens allowing flow back to the tank(s). The shorter the fuel line between it and the carb, the better.

 

[B-man]

I am leaving it all in.. With the assistance of Paul in this thread. I found the valve that will work in the rig. Just got to order it.

That is another thing I have to fix on the Bronco. Whoever ran the fuel hose from the carb to where it meets the return lines, left a bit of slack..I have a about 6 to 7 inches too much of hose there.