My recent great deal on a 1979 Series II XJ12 became less than great when I started to pull the fuel tanks for a clean and seal job (POR-15 - my favorite).

Removal of the lower body panels covering the tanks revealed that the tank bottoms were missing, rusted away to nothing. Addionally, the aluminum filler assemblies had become one with the steel necks in which they reside. Two weeks of daily applications of PB Blaster, heat, and a good pounding got the left neck loose, but the right required use of an air chisel and its destruction.

I was lucky enough to find a 1976 XJ6 parts car with good tanks, and alot of other bits I'll be needing, with the tanks already removed and ready to refresh. What I didn't notice was that the '76 carb tanks are different than the '79 FI tanks.

• The '79 has the pickup fitting in the bottom and the sender in the front,
• The '76 has the pickup with internal pump mounted in the front and the sender in the rear

Rerouting fuel and electrical lines is a given in this job, but I'm looking for advice on the fuel pickup. As I see it, I have four options to use the '76 tanks in the '79 XJ12:

1. Drill a hole in the bottom of the tanks, braze in a fitting, somehow mount a screen in the tank.
2. Make a pickup tube, screen, and a blank for the front hole of the tank, braze or silver solder it all together, and get a rear mounted sending unit.
3. Same as 2., but put the pickup in the rear and the sender in the front.
4. Use some other pickup that is close and modify it to fit the '76 tanks.

The tanks have been open to atmosphere for at least the last four years, so I'm not worried about brazing on them.

Has anybody found a pickup assembly that will drop into one of these? Looking at the parts book doesn't show a Series II part that would be an easy swap, but there's bound to be something that would be an easy replacement.

 

Don't want to hijack your thread, but I am working on a second xj6. This one is a 1982. This one will be treated with an LT1 motor. The fuel tanks are shot in this car and I refuse to spend 700.plus dollars for two tanks. I went down to the marina and I am having a 20 gallon aluminum fuel cell custom built to fit in the well where the spare tire goes. The guy made a template and when done and installed the trunk floor will be flat, insulated and covered. I will have the tank in about two weeks. Cost? $350.00. I am in the process of making the plate assembly for the sender and fuel pickup. Will post a picture of this when I am done. I have masterfully (lol) changed the innards of the original jaguar fuel gauge. It now works as follows. Empty 0 ohms; Full 90 ohms. This will be compatible with a universal sender unit that cost $20.00. I used the innards of an Autometer gauge and assembled it to the original jaguar gauge. Tested and working as it should. All i have to do when the tank is done is to adjust the height of the sender and the length of the float arm.

 

I also tried another generic sender assembly. Empty reads 1/4, Full reads 3/4 on the original jaguar fuel gauge. I am trying to calculate the resistance factor on both ends to figure out which way to go. I will know when my tank is full, I need to know when it is empty. So for now I am trying to calculate the resistance at the empty end. Will post results in a couple of days.

 

The fuel gauge sender is 240 ohms when empty down to 20 ohms when full....
the other readings are for non Jag/Smith gauges.

 

denraden1 - its not a hijack 'cause you're helping me out with another idea for my fuel tank problem. How are you planning on running the filler? That sounds like a bargain for a custom fuel cell, I doubt I could find someone here in northern Indiana to do that for that price, but its worth looking into. I had considered mounting a cell to the shelf in the trunk, leaving the spare tire in the well, but found this parts car whose tanks I should be able to make work.

Roger Mabry - thanks for the info, that will come in handy if I have to rig a circuit to work with a non-standard sender.

 

Will be removing both tanks. I am going to run the filler pipe through the now empty space where the tanks were. Left or right. Not sure yet. When I install the tank I will decide. I also looked at an xks / xjs?? tank that someone has in Indiana. (Listed on Craigslist) to fit on the platform but it is two inches too long. My trunk hinges are in the way.