She’s been trouble free for a long time now and then this!!! I knew I was tempting fate when I told my wife that we could get in her and go anywhere, she’s super reliable!!! Should have knocked on wood!!!
I know it’s a common problem but cannot remember which valve I need to be looking at! Running on left tank and all is good, running no. Right tank, left tank overflows!!!

 

I *HATE* it when that happens!!
It's a good thing that drain works or you'd have a real mess on that paint.
(I can tell you how I know that)
(';')

 

These cars need a check valve like aircraft to bleed off water and check condition of gasoline. Inevitable given the age, culprit is probably the changeover valve but the reason is probably dirty tanks.

 

I think it's a non return valve in the wheelwell is stuck closed. One is normally open, the other normally closed, but I can't remember which side is which. I'd replace both.

Here is the testing procedure: https://www.jag-lovers.org/newbies/s...hangeover.html

 

thanks that gave me the info I needed, left valve is normally open!!!!

 

Well, it looks like I'm swapping out both valves!!!! Got sometime this afternoon to check everything out and of course it’s working perfectly now!!!! I can switch the tanks over and by holding open the flap, i can see the fuel returning to whichever tank I select!!!

 

Could be the tank switch on the dash that moves power to the correct valve when you switch tanks. Push switch in and out multiple times to clean contacts.
Rgds
David

 

good idea, can’t hurt for sure

 

Suggested trunk sign for all XJ's

 

I've taken that switch apart and cleaned the contacts. Not too bad a job and it did the trick.

Bill