XJS Fuel Tanks

[steve580]

Hi, my XJS V12 HE has been off the road for 20yrs, both fuel tanks need to be replaced or refurbished, I'm in the South Staffordshire area, any suggestions would be greatly appreciated.

[davidr]

Hi Steve580 and welcome to the XJS forum.
When you say both fuel tanks do you mean the main tank and the swirl pot that sits below the battery?

[steve580]

Hi, yes sorry, I do mean the main tank and smaller feeder tank/swirl pot under the battery. I've been advised that a company in Cornwall can supply kits that you can use to clean and apply a new coating to the inside of the tanks, I understand it's not an easy task and was hoping to find a specialist company that did this process.

[davidr]

The first thing to do is to carefully look at the bottom of the main tank. They suffer from 2 issues. Firstly they sit on a foam pad that retains moisture and will eventually corrode and perforate the bottom of the tank. Many an XJS has a whiff of fuel in the boot and cabin as a result.
Secondly, Jaguar in their wisdom decided to fit a rivet up through the panel that the tank sits on that can also cause a hole.
You may find it easier to source good second hand tanks if your own are beyond repair?
There are products available for repairing and relining tanks. For example https://www.frost.co.uk/por15-professio ... ealer-kit/
I've not used this myself but maybe others have and could comment?

[JimMann]

If you are sure you want to repair / restore the existing tanks in your XJS, I used the guys at Devon Bike Tank Repair to restore the original tank of my Kawasaki Z1000 motorcycle. A really good job, cutting open, blasting and then welding back together before lining the internals. Seriously expensive though to retain originality on a Classic Japanese bike! Possibly made more expensive by the fact that replacements (new) are just not available.

https://www.biketankrepair.co.uk/

Jim Mann

[steve580]

Thank you both for your reply. The main fuel tank looks in very good condition from the outside, I have removed the fuel sender unit and looked inside the tank, it looks like it was painted inside or had some sort of black coating which has now flaked off and the tank is rusting. I added 7 gallons of fresh fuel changed the fuel filter and started the car. The engine does run but then cuts out, all the debris from the main tank has settled in the swirl pot/pipes, the swirl pot has been removed cleaned out of any debris but without changing or cleaning the main tank I feel this will always be a problem. I have found an after market main tank but the swirl pot is no longer available. Would you try cleaning both tanks or replace the main tank with the after market tank and send off the swirl pot to be refurbished. Many thanks

[JimMann]

Personally, if there is a suitable after market tank available, I would go down the route of replacement. In regards to the swirl pot, check the Breakers for a replacement. Yours are failing because of the length of time sitting idle, if you can find a regular use second hand unit, that would probably be a better route.

Jim

[davidr]

I would take the tanks out to check their condition. The main tank in particular needs a close examination to make sure that the underside has not perforated from the outside. It's not possible to do this with the tank inside the car.
There is a small filter on the end of the pick up pipe in the swirl tank and it's important that this is clean and, as it sounds like you've found, this will suck up debris and cut off the supply.
We ran an article on this in the magazine recently.

[ptjs1]

The swirl pot system was used primarily to counter fuel surge problems in the main tank under cornering etc.

Revised baffling in the tank eliminated the need for the swirl pot and Jaguar dropped it for later XJSs.

I'd be minded to ensure the integrity of the main tank, re-route the pipes and filter, get rid of the swirl pot altogether and just always keep the tank at least 1/2 full.

Cheers

Paul

[steve580]

Thanks everyone, I will remove tanks tomorrow and inspect the bottom of the main tank. Dependant on findings attempt to clean or replace with after market tank, regarding the swirl pot I have cleaned the filter and tank but I'm sure it will need cleaning agian.

Many thanks again, Steve

[SimonR]

The first thing to do is to carefully look at the bottom of the main tank. They suffer from 2 issues. Firstly they sit on a foam pad that retains moisture and will eventually corrode... Secondly, Jaguar in their wisdom decided to fit a rivet up through the panel that the tank sits on that can also cause a hole.
There are products available for repairing and relining tanks. For example https://www.frost.co.uk/por15-professio ... ealer-kit/
I've not used this myself but maybe others have and could comment?

I'm just answering here in case someone searches this in the future. I have experience of fixing an XJ-S tank with the Frost's solution, albeit I needed to purchase a second can of POR15 as the tank in our cars is large and has baffles inside which add to the surface area.

My car's tank appeared corroded on the seam at the bottom edge of the tank, however, on inspection, the problem was caused by a spot-weld, where a baffle was attached to the inside of the tank. The problem was characterised by a fuel smell in the boot that could not be traced to any of the pipe work and never went away.

The process is straight-forward enough - empty the tank, undo all the connections and get it out of the car. Remove the sender from the rear face of the tank, then tape all the holes closed, except the filler neck - I just used masking tape. Make sure you stop POR15 getting into any screw threads. Once you've prepared the tank with the two-stage chemical treatment, pour two cans of POR 15 in, seal the filler neck and then give it a really good wang around - all angles, multiple times until you're happy it's coated all surfaces inside. Then pour the excess out (repeating the multiple angles treatment) to get as much out as possible. Leave the tank flat on the ground to dry so that any excess pools along the bottom surface.

Once it's dried, you can take all the tape off and use a drill bit to break open all the inlets and outlets before re-installing the tank in the car.

Re-installing is a two or preferably three-person job - the tank only just fits in the gap that the tailgate allows and it's really easy to chip the paintwork with the sharp edge of the tank if you don't have assistance to align it properly. Don't ask me how I found that out

My new car has the same fuel smell as the old one so I suspect I'll be doing this job again soon, unless I can trace it back to a hose. It doesn't bother me though as the repair on the old car lasted for ten years and was still going strong when I sold the car. Very much a case of fit and forget.