I hate the idea of abandoning my beloved dual tank setup but they are rusted, the vents are clogged, the switchovers randomly fail and pumps/filters clog.

Soooo...I am considering a modern aluminum in-trunk tank to go under the package shelf and leave some amount of trunk space.

I found one post about someone who did this and messaged, but wondering if there are others who have done this.

After some reading, I may have to fab some changes to allow the new fuel level sensor to work. Also not sure about joining old style rubber fuel hose to modern fittings..but gotta be a way.

I don't mind filling tank by popping the trunk instead of having external fill cap.

Thanks for tips and flames OK too 😁

 

Well, I feel your pain. I have two xj6's and have been through the fuel tank issues more times than I care to remember. The secret to a reliable system lies in new or as new fuel tanks, even a fine brown colored fuel will get past all fuel filters and make fpr's, return valves, changeover valves and fuel pumps all malfunction. When the car was new, the new tanks and valves lasted many years without issue. So the secret is new fuel system from tanks to valves, clean lines etc... But it all has to be done at once then you have a happy cat for years again. Two new tanks and valves probably wont cost any more than a universal tank and the time to make everything work properly. Those new tanks are money well spent.

 

Another issue is tank capacity. You'd need a 110 litre tank to match the existing fuel capacity.
Not sure what this would be in US gallons.
Anything less, given the vast distances is not something I could live with, here in the kangaroo country.

 

The only such installations I've seen (maybe 2 or 3 over 25 years) have been installed over the spare tire well. I wasn't impressed with the look, personally. And it means giving up the spare tire.

The ECU, sunroof motor, and other electric goodies would be blocked if you put a tank under the package shelf.

Anything is possible but there would be compromises, as always.

Considering costs, effort, results, appearance, convenience.....I'm not sure the juice is worth the squeeze.

Cheers
DD

 

All great points..but the root cause is a steel tank! If I am going to keep traditional setup, then is there a high quality stainless tank available or better yet a good plastic or aluminum option?

Replacing with a steel tank just resets the clock on a slow fade to future problems.

 

The new tanks are galvanized so rust is much less of a concern.

 

Would using a product like POR-15 tank sealer on a galvanized make it close to rust proof as possible?

 

It's been a long time since I tried to seal a tank but I think you have to etch the tank before sealing. I don't know if etching would remove the galvanizing found in new tanks but I suspect it compromises it to some effect.

 

Nooo.... The original tanks weren't galvanized, how long did they last? Btw... I've sealed many tanks over the last 40 years, all with good success. But I've bought the new "galvanized" or powder coated? tanks and I would not compromise such a nice coating to slosh some por15 on it.

 

For what it's worth I had my 2 fuel tanks steam cleaned by a radiator shop about 8 years ago. I did not seal the tanks. One of the tanks had pin hole leaks that was repaired with solder.
8 years later and they are still going strong. I recently drained the tanks to replace the pickup filters and there was little to no rust in the tanks. I never let either of the 2 tanks to drop below 1/2 tank.

 

I would not use POR 15 either. Had a V12 E Type come through that someone had done a POR15 treatment to the tank and a year later it was all flaking off in sheets, completely filled the fuel system with particles of the coating that failed. Made a big mess, the entire fuel system had to be cleaned out.

I took off the access panel on the top of the fuel tank and this is what I saw:

 

At the time of conversion, the PO had Nix's tanks sealed with the same compound used in aircraft fuel tanks, which name escapes me ATM if in fact I ever knew it. That was 1986 and there is still NO evidence of flaking or rust, and I have had NO fuel problems during my ownership.

Of course, I don't allow fuel level to sit unused below half tanks either, as condensation in this locale is Terrible in winter.
(';')

 

The aircraft tank sealers ( at least years ago, VOC regs may have ruined it by now ) are serious stuff. I fixed a roof / windshield hole on my dads old farm truck using some once, lasted for years until the rest of the body rusted away from the seal !
Using them would require removing the tanks anyway, so I'd recommend just getting new galvanized tanks instead of rolling the dice on old rusted ones.

Cheers,
Brian

 

yes, save the money and replace the tanks. Twin tanks add interest to the car.

Check prices, there are several suppliers now, one in Canada, one in UK, (Martin Robey), one in Germany. Not sure about USA.

 

RockAuto is a good place to buy them in the USA. You can use my coupon code 291091386258162451 for 5% off - it's valid until Feb 14.

 

Regarding the problem of condensation, there is a theory methylated spirits (denatured alcohol) combats this problem.
I have been advised to add 1 litre per side when re-filling, so if the fuel levels drops & car left un-used for a while, any water is absorbed.
Any thoughts?

 

Many, probably too many, years ago Wynns had a product "Dry Fuel" and it was reported to do what you mention with the Metho.

Metho I used in the "old" Jags etc and had no issues.

Not sure on a ltr, we just poured a coffee mug in and moved on.

OK, we be DRY here, so very different climate to you.

Our fuel is also different ??, dunno, it comes from Singapore now.

Hoe any of this "pour in" stuff annoys O2 sensors etc, no idea also.

 

That is not POR 15 - POR 15 is silver and sticks to everything -I have never had an issues with it

 

Jose, who is the vendor here in Canada. I may have to use their services at some point. Ian

 

not sure Ian, but it was in Canada that they started reproducing the XJ tanks years ago.

Would have to search old threads.

try here:
​​​​https://www.thewrenchmonkey.ca/auto-parts/jaguar/xj6/1985/air-and-fuel-delivery/fuel-tank/