Need Help...Fuel Tank..Aux Tank Questions

[Rmally]

Hey Folks,

I am having some major confusion over the fuel tanks....main and aux.

First of all on the left side dash I have a fuel selector switch for the gauge. It reads full when its on the aux tank but is pegged to empty when switched to the main tank.........and the main tank is FULL.

Next, is the fuel tank selector switch on the floor printed upside down for main and aux? The reason I ask is this. I took the bronco out today and noticed my fuel gauge read empty in aux and main, previously it was at 1/4 tank on aux but has been at paint shop so I'm sure they ran it low. I headed straight for gas station and the bronco died on me three times in 2 miles. I switched tanks....no good. I rolled it down the hill and when I was level it fired back up and I coasted into gas station.

I tried to fill up rear tank (that's the main right?) but it was already full. So then I moved to the forward tank (aux right?) and it was empty, put about 6-7gallons in it and it started right up. Also the fuel gauge read FULL. I switched back over to the main tank and it started sputtering.

So, I left the dash selector on aux (gauge reads full) and the floor selector switch appears to also be on aux and it ran fine all the way home.

This may be a stupid question but when I lean over to look at the floor selector switch aux is to the left and main is to the right...is that correct or is my plate upside down?

It appears I'm only running on aux, how can I get the main tank back online?

Let me know if you need further info or photos.

FYI...71 model

Many Thanks,

Randy

PS...pictures of the new paint coming soon, will start a new thread when I can get some photos and trim back on.

 

[Rmally]

Here's a few photos if it helps.

Can someone confirm that the floor selector is on Aux based on the photo.

The other pictures are showing the fuel reading with Aux and Main from the dash knob.......Full=Aux......Empty=Main however both are full of fuel.

Some crappy garage photos of the new paint. It still has to be buffed so it will look a little better once that has been done.

Thanks again guys for any help.

Randy

 

[Fireball05]

Your under seat setup is correct. Meant to be "upside down" so you can read it peering between your legs. This controls which tank you're pulling from.

Looking at side of vehicle rear tank filler is main. Front filler is aux.

The dash switch only changes which tank the fuel gauge is reading. Nothing to do with where it's actually pulling.

Others will have to give you more info to check the gauge wiring.

As far as gas delivery get underneath , start at the selector valve and let us know what you see.

 

[Rmally]

Thanks fireball, so the switch is currently on Aux in the photo correct.

I will try and get under the bronco tomorrow and get some more photos.

 

[thegreatjustino]

Sounds like your AUX tank and switch are working fine, but the Main tank and gauge have issues.

 

[Seattle66]

I feel your pain. I had basically the same situation on Monday. Bronco started acting like it wasn't getting any fuel even though the gauge was reading quarter tank on aux tank. It died at a busy 4 way stop with about 10 cars behind me. Switched to main tank which I know had at least 9 gallons in it and no luck. Had to push it out of the intersection. Went and got some gas, put in the aux tank, switched the selector back and it started right up.

 

[.94 OR]

Aux tank is plastic and Main tank is steel. I have a better time getting clean fuel from the plastic tank since mine sits most of the time.

I stamped an "F" and an "R" in the sides of my floor selector valve toggle and then painted the indent with a bright yellow paint. It is a lot easier to look down and see which tank I am pulling from that way.

 

[Rmally]

My concern is that I don't think I'm pulling from the main tank at all. Hopefully will get it sorted soon. This is my first EB and these tanks were causing some confusion......but I love this thing!

 

[jckkys]

I would pull the sender/pickup assembly in the main tank. It sounds like the float on the sending unit is full of fuel. I've had that in several cars. The gauge reads empty all the time when this happens. The pickup filter is part of this and may be plugged. If you get it out buy a new pickup filter, to be sure it's good. Bronco Graveyard has them for 6 bucks. They also have new brass floats.

 

[blubuckaroo]

The reality is, the positions of your switch and valve may have been changed. You'll need to check it out.
I have some advice though. The best modification I've done is the replacement of the fuel valve with an electric one.
Up till tis point, every member of our family had run out of gas because they didn't understand about synchronizing the switch with the gauge.
With the fuel valve mod, you switch the gauge and tank together. Problem over!
Also, now there isn't the occasional fuel leaking onto the carpet from the old manual valve.
And the biggest plus...
The electric valve cost me less than the old mechanical type. ;D

 

[MarsChariot]

Yes, what blubuckaroo siad: On some Broncos the handle end point sleft for the main tank...and on some it points right. Both our Broncos were the exact opposite for a long time, and I could absolutely never remember which was which. Even after I converted the Chariot to an electric, I still couldn't remember what the other Bronco sequence was. You just gotta flip the switch and watch the gauge and figure which direction works for you. If we were smart we would have put a label on top of the handle. But where is the fun in that?

 

[SHX669]

I always just remembered that the "pointy" end of the valve handle under my feet ponited opposite of the Main and Aux positions on the dash bezel. Some guys figure the " butter knife handle" end points the same way as the dash switch "knob" - assuming everything is piped AND wired correctly . - easy huh- LOL.
I resisted the electric " tank switch/valve" but after finally installing one I'm glad I did .