odd auxiliary fuel tank questions

[mharshman]

Hello all,
I just recently have purchased my SIII V8. In a weeks time, the fuel pump (I suspect) is not working properly. In Famous British Fashion, I wacked it with a hammer, started right up. (Ordered a new one) Having this issue lead me to check out the whole fuel system. I have a normal rear Fuel tank, and after it (Towards rear bumper) is an auxiliary fuel tank.
Having checked the LR Optional equipment manual..... Only ONE picture of it on a Frame diagram Round corners, not box-y like others (pic not fuel section). But in the Auxiliary tank section in manual, no other pictures of that tank. Futher more there is no manual switch to go from on to the other? I can see they are connected, and the over flow hose from the filling point, goes to the Auxiliary. There is no sender from the Auxiliary fuel tank that I can tell.
Anyone have a clue on this? How does this work? Do they equalize? No filling point, port, cap either!!!! How do you fill it, how does it pump?
I have a few dashboard switches that do not operate anything. Could one of these be a electric fuel switch from one to the other?
Any info would be appreciated!! Thank you, Matt

[disco2hse]

the fuel pump (I suspect) is not working properly. In Famous British Fashion, I wacked it with a hammer, started right up. (Ordered a new one)

I assume you are referring to the facet pump. Do you have two?

I have a normal rear Fuel tank, and after it (Towards rear bumper) is an auxiliary fuel tank.

Umm, what?

A rear tank behind the rear tank? Memories of Pinto...

Having checked the LR Optional equipment manual..... Only ONE picture of it on a Frame diagram Round corners, not box-y like others (pic not fuel section). But in the Auxiliary tank section in manual, no other pictures of that tank. Futher more there is no manual switch to go from on to the other? I can see they are connected, and the over flow hose from the filling point, goes to the Auxiliary. There is no sender from the Auxiliary fuel tank that I can tell. Anyone have a clue on this? How does this work? Do they equalize?

This has been discussed on this list, with regard to military versions and some Australian civilian models. I wonder of those posts were lost during the upgrade?

In the military sense, there is a switch between the speedo and temp/fuel gauges. Flicking the switch (de)activates a relay that starts one or the other pump and links the respective sender unit to the fuel gauge on the dash. Obviously, each tank has one pump. The return from the carbs has a solenoid so that the right tank gets the overflow from the carbs, depending upon which way the switch is set.

No filling point, port, cap either!!!! How do you fill it, how does it pump?

Can't answer that question. You should have a filler on the same side as the side tank, ahh but hang on. You said you have two rear tanks, one behind the other...

I have a few dashboard switches that do not operate anything. Could one of these be a electric fuel switch from one to the other?
Any info would be appreciated!!

Don't know. Can't see them.

[mharshman]

Yes, I did a search through the forum. Came up with nothing about rear Auxiliary tank, just under the seat kind.
On page 35 in the LR Series III, V8 Optional Equipment Manual, there is a picture of the eact one on the drawing. This drawing is explaining the PTO, not Auxiliary. Further back in the Optional Equipment section on Auxiliary Tanks, the V8 Auxiliary does NOT have a picture, just parts list. Main fuel point fills main tank, main tank has three lines. One to pump, one for the return, one to Auxiliary. (Sender of course) Axuiliary has two lines, one from Main tank, one to main fuel port (Over flow).
As for the pump, Only ONE Facet pump. No switch between the Speedo and Fuel gauge, just Trip reset rotator
Today I filled up with petrol. Filled all the way up till almost pouring out on the ground. Truck would not start. Can hear the Facet Pump clicking...... Gave a few taps anyway. Nothing. Checked the fuel tank filling port. Gas was not visible any more..... As if it equalizes between the two. This was never a Military Model. Custom purchased, sent to Kuwait for many years. Cleaned the points on the Distributor. Got a battery Jump, started after a few turns? Battery seems to be good, charging it now. Do not think this is a battery issue.
Sorry getting off topic...... Two tanks, fuel lines connecting each other, no manual switch, one fuel pump, one filling point. I understand that several Military vehicles have two tanks and they equalize beween the two. Most Semi Trucks / Lorries do the same. Just wondering if anyone has this set up, or knows about it.

[disco2hse]

I shall try to split up the post, to make it readable.

On page 35 in the LR Series III, V8 Optional Equipment Manual, there is a picture of the eact one on the drawing. This drawing is explaining the PTO, not Auxiliary.

This is on page 1I 11 not page 35. If anything, it is 68 pages from the front cover.

The tank is in the parts catalogue on page 10 06.

Main fuel point fills main tank, main tank has three lines. One to pump, one for the return, one to Auxiliary. (Sender of course) Axuiliary has two lines, one from Main tank, one to main fuel port (Over flow).

Have never seen this before. Sounds like a bodge. Some pictures would be useful. Might explain why you don't have a separate filler although the rate at which fuel would transfer from one tank to the other, it could take a very long time to fill both tanks. I think I'd want a 50mm pipe between them if I were to do that. It is possible you might get overflow issues if both tanks are full and you get stuck on a sidling.

As for the pump, Only ONE Facet pump. No switch between the Speedo and Fuel gauge, just Trip reset rotator

Got the idea now.

From your description, it sounds like the fuel pump is on its way out.

Back to your first post. Sounds like an easy job to replace the fuel pump. Personally, I favour the facet pumps but they are expensive. There are plenty of solid state pumps around nowadays that are less costly. You just need to find one with the same pressure and flow rate as the one you have now.

The pump will be stamped with the part number. What is it? (I am assuming it may not be standard).

[mharshman]

Sorry was refering to the Adobe .PDF page number (35), not the actual page number on the actual document. Actual manual page would be 1E 02. (PTO) PDF page 71 is just text of the V8 auxiliary. No picture on how it is hooked up.
As for the Facet fuel pump, I already ordered a new one. I didn't think it was all too exspensive. Then again, I want my truck up and running, would pay a bit to get that done. It is my daily drive. It does not sit in a garage, and driven on weekends. The pump is pretty much rusted. Can not see any number on it. Standard size facet pump.only
Thanks, Matt

[disco2hse]

Glad to hear it is sorted.

Hope you got the right one. There are a number that are close but not the right flow rate, etc.

[mharshman]

Crap! Hopefully it is....

[FenTiger]

I think what we have here is a school boy error. To the uninitiated, it would appear when removing the two inspection panels in the rear that you have two tanks. There is just one tank with a recess in the top to accomodate the cross member. The link pipe is just there to allow it to vent and fill up to the top on both sides of the cross member. Have you actually had a look from underneath?

Photo of what it looks like:

[firemanshort]

Yea ... what Fen Tiger said about the tank shape. Double check your vent hose pipes that link the two top sections. If they are kinked then you will not be able to equally vent the air in the top tank space as you fill it with gas (petrol).

The Facet pumps can be found at a Napa parts store. That is where I bought my last one (~ $150 USD) I think they cross match to a diesel sail boat motor or some such nonsense. Anyway, this pump is very popular for a lot of applications (but since the Stage One was not a NADA vehicle the pump is not cross listed to a Land Rover).

[mharshman]

Well you maybe right then. I have not dropped the tank gaurd / holder to see. From the top, one is welded square, the other is has round edges. To further make things complicated, one is black (looks newer) the other is more older rusty looking. See pictures.
BUT..... That is why I am asking. I could be very wrong about this.
I did fill up, than wait ten minuets later, and filled it up again? It took time to settle?
But a five hook up is there. Is that the same for yours? One to fuel pump, one for return, one for overflow, are the other two just for venting then? And not actually hooked together?
Again a new idiot user.... I learn by asking and breaking...

Thanks, Matt

[drifter]

You are not seeing things...

I have both - the square edged 'normal' one and a round edged one that tucks up between the filler hose and the rear of the tub (makes it interesting when drilling holes) and it is a total pain in the butt to change the number plate light (which happens to be on that side on my vehicle).

Up in the engine room you have a fuel pipe that comes to the carb(s) via the fuel pump.

Excess fuel is routed all the way back from the front to the rear - to this expansion tank which has another pipe that goes to the main tank.

Mine is a 1980 model which clearly has it.

[mharshman]

So in my second Hand hole, I am seeing the same main tank, and the cross member? And NOT (what I think) is the main tank and an Auxiliary?
It's like an optical illusion...... Well for me at least.
What is your typical MPG? My sender is bad, My gauge reads full all the time. It is being replaced this week. Not fun to run out of gas..... When gauge says "Go ahead, Drive further!" Luckly I ran out next to my office.

Thanks, Matt

[drifter]

So in my second Hand hole, I am seeing the same main tank, and the cross member? And NOT (what I think) is the main tank and an Auxiliary?
It's like an optical illusion...... Well for me at least.
What is your typical MPG? My sender is bad, My gauge reads full all the time. It is being replaced this week. Not fun to run out of gas..... When gauge says "Go ahead, Drive further!" Luckly I ran out next to my office.

Thanks, Matt

In the 2 inspection hatches you will see the main tank. To see if you have the same auxiliary tank I have, stick your head in the rear mudguard area and look to the back of the vehicle.

Typical MPG? Nothing typical about these I have been mainly using mine as the daily driver - to and from work - 25km each way with half as town driving and half as open road driving - mainly flat - couple of hills... if there is little or no wind I get about 14MPG so it's a bit more expensive than the Discovery to run - but it's helping keep some of the wear and tear off the Disco...

My sender wasn't bad, it was just badly placed and the float was rubbing on the edge of the tank so I was getting erratic readings. If your gauge reads full all the time, is it the sender or an earth on the wire from the sender to the gauge?

[mharshman]

As for the sender, I just decided to buy a new one. The great thing with this vehicle is that it has all the paperwork on all parts replaced since 1980. The Fuel gauge was replaced in 2009. So I am guessing that is still good. I did a voltage test on the wire. Not a constant voltage? But I can adjust the Sender if it is indeed rubbing the side of the tank.
Thanks for the info.
I get about 15 MPG. I hope I can adjust the Carbs correctly. The running with the choke pulled, is getting old quick. I know I am pissing away fuel on that alone. On rare occasions, like making a left turn (choke off), I down shift and the truck will cut out. While still rolling, I can restart it fine. Just a pain, and I know that isn't right.
I believe the truck was not driven all that much before me. It is my daily driver also.
I estimate a new frame will be needed in about another three years. Oh joy! That will a fun project! HaHaHa

-Matt

[disco2hse]

I am getting 17.6MPG (imperial, that equates to just over 21 gallons US) on the open road. That is cruising around 95-100km/hr.

Tune them carbs and get the spark sorted.

You might need to replace the voltage stabiliser if other gauges are doing weird things.