1970 Barn find not started since 1984

Bought this XJ6 several years ago and put it under a cover waiting for time, money and enthusiasm for restoring it. Was a member here for my other XJ, a lump, and found the resources to be very valuable. I’ve met a fellow here in Tucson, AZ, USA that is in the final stages of cleaning his Series 1 up and thought I should give mine a try.

Has not been started since 1984 as far as I can tell, when I bought it I spit some Marvel oil in each cylinder through the spark plug hole and manually turned the engine over. Part of what has held me back on starting the project is the dread of dealing with the wing tanks. I am posting today looking for some advice to start with on how to best deal with the fuel tanks. It looks very difficult to remove, and a nightmare to re-install. Thankfully the entire car is completely rust free, unfortunately every rubber piece is rotten or missing from pack rats.

Thanks for any encouragement, it is a beautiful car.



Welcome back, Rock,

are you sure the tanks have to be done? - If the car is rust free chances are the tanks are still o.k. Before diving in I’d peek into the tanks with an endoscope that you can plug into your smartphone or laptop computer.

If you need new tanks the job is not really super-hard - it is just a lot: you have to remove the rear bumper, then the quarter panel before you can even start to undo the filler cap.

Good luck


75 XJ6L 4.2 auto (UK spec)

I do have an endoscope, I will poke it in there. I guess I just assumed there would be a sticky mess in the bottom and so I would have to pull the tanks to clean that.

What Jochen said plus perhaps lift the lids on the float bowls. If there’s been a problem in the past you might have sediment in the bottom of the bowls, also may be visible in the glass bowl in the spare wheel well. Paul.


That’s very likely, but IMO you can get them really clean in situ by removing (obviously empty them first) the sump from both tanks. Ser 1 and European carb’d Ser 2 like my XJ6C have the fuel gauge sender on the front side so if you remove the rear wheels and open the small round panel (just four small screws) you can then remove (by turning the lock ring) the sender unit and you get a good look and some access for a brush etc to clean the tank bottom.

Anyways that’s how I do it. I have had both tanks out for repairs and if you take them out it’s an excellent opportunity to also wire brush and apply rust prevention stuff on the inside of the wings, especially the seams, fuel filler box etc.


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With a car standing since 84, Rock - attending to tanks would not be first on my priority list…:slight_smile:

xj6 85 Sov Europe (UK/NZ)

Nice car indeed Rock!
Don’t assume anything before you check, for good or for worse…

First thing, see if you can rotate the engine.

All the best.

Interesting, I had hoped those small round panels in the wheel well could be useful in determining the condition of the tanks.

The other details in firing up an old motor are familiar to me, I’ve done a few of the steps already. The engine rotates by hand. On a normal car I would have already dropped the fuel tank out and had it power steamed, but these Jags make that a difficult procedure. I’ve just learned the tanks were steel, don’t know why I thought they might be aluminum.

The original reason for the car being parked was radiator leaked. While that was being dealt with the subject came up that the teenage girl who had just been given the car hated the color and did not want it. A family argument developed and the car was sent to one of several large barns on grandfathers property and ignored until the estate was sold following his passing. I’m sure it was quite beautifully restored when put there in 1984 but time and heat put some age on the leather and rubber. They included a re-cored radiator.

There is a large plug and a small plug within it at the bottom of the tanks. Not hard to undo. See waht if anything flows when you open them. dump in a gallon of kerosen or similar if nothing flows. See what that small flush will be laden with, if any thing.

My guess would be ‘dead’ gas or nothing at all.


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Yes, as Carl mentioned, you can remove the big plug and see what comes out. It will be tale tell sign.

tanks are easy to remove, the hoses can be a bugger, but they probably need replaced anyway.
i have a set of S1 tanks from my '71 if you find a need for replacements


even better if you’ve got an endoscope! Purpose of peeking in is to check the general state of the tanks. If you don’t find serious rust, you can pop a bottle of champagne as the tanks may remain in the car.

The debris and mud in the bottom can be attended via the bottom drain plug. Messy, but simple.

Good luck


75 XJ6L 4.2 auto (UK spec)

Thanks for the encouragement, it may not be as bad as I feared. Have the bolts soaking now, I will get into it Saturday morning.