I just had an issue with my driver's side tank spewing gas out the overflow drain. Possibly a buggered changeover valve? Here is my dilemma, are my tanks original or replacements? The car is new to me and only has 24,000 original miles. Injectors were rebuilt, but I don't believe, as indicated by the 1984 date on the fuel hoses in the boot, that any other parts of the system were changed. With only 24,000 miles the tanks could be original and look very clean looking in from the taillights. I have two new tanks and they are galvanized. The tanks in the car look like bare steel. Original?

Is this what an original drain looks like?

Though they may look nice on the outside I wonder what the inside looks like if they are original tanks, especially if they were not full when stored over many years.

Advice?
remove the sender and see if any rust is present?
If rust is present then I am going to assume the tanks are original and need to be replaced, especially where I have two new ones on hand.
Can the changeover valve be cleaned of rust or do they get blocked up solid?
The return valves, the ones in the wheel wells, are new.

 

If the tanks are original they should have foil on each side to prevent sparking from metal on metal contact. The tanks I replaced these with didn't have it.

 

Those are nice looking replacement tanks as evidenced by the single small drain bung on the bottom and unpainted color. They look nice on the outside and I'd love to see how they've aged on the inside (remove the senders behind the tail lights and look through the hole with a flashlight and camera).
Just re-read your post. Yea, may have rust again. There is some rust rust showing around that drain bung and it looks to be from the inside. That is def not an original tank. Changeover stuck causing overflow, same old problem. Glad you have a pair of new galvanized tanks!

 

Agreed, replacement tanks. I drained both tanks and the fuel was nice and clean.

The car sat in a garage in Florida for probably many years and was "reconditioned" when sold as part of the PO's estate. The injectors are new, tanks are new, probably new sending units and the changeover valve looks new, but no way of really knowing.

I did remove the changeover valve and applied 12 volts to it and it clicks and I can blow air through both ways when I change the wires around. Does this mean the valve is ok? I didn't have a helper, but I assume when I select each tank with the switch on the dash I should also here the valve click. Any chance the selection switch on the dash causes issues?

The fuel return valves in the wheel wells look a bit "crusty". The person who got the car back on the road after its long slumber never replaced the splash shield that should be installed to protect them. I have two off a donor car that I had blasted and powder coated. Could a bad return valve be causing an issue as well?

 

Changeover valve should close completely in one direction depending on voltage off/on. Is this what you’re getting? Sometimes they will only partially close causing the same overflow condition. And yes, the return valves will cause the same symptoms. All symptomatic of trash getting into the valves, thats why I always stress clean fuel tanks, lines and components double thoroughly before replacing valves with new. Dont ask me how I know, im a hard learner. Even with best efforts bits can remain in a component only to come back later and is prob what you’re dealing with now. As clean as that fuel looks though, i’d say you’re in pretty fine shape.

 

Also a good time to add inline 7/16 filters in the rubber lines just out of the tanks.

 

I picked up two new fuel return valves from SNG Barratt seeing they are just up the road from me. Finding 1/2" universal inline fllters wasn't too hard, but not exactly easy either. I ended up getting two off Rock Auto. They are Wix filters part number 33299. I plan on putting them in just before the change over valve.

 

MSG, iirc I ended up fitting 7/16 fuel line or filters back there on my 86, can't remember exactly why but there was a better fit reason. I'll try to have another look soon, I do remember struggling with 1/2in for some reason.

 

I decided to order the correct, I believe, 12mm ID hose that comes out of the tanks and feeds the changeover valve and then the fuel pump. When it comes to fuel hoses, I like to replace them with the size that originally came on the car. I remember replacing the hoses from the fuel rail to the injectors with something close to the metric original and I had issues with them leaking. Ordered the correct size that came on the car out from the factory and no issues. I believe it was the same size hose that came on some VW vans, and it came from Canada.

 

Ahh, now that could explain a lot! Thanks for that tidbit

 

The 12mm ID hose and 1/2" (12.7mm) in-line filters were a nice tight fit. No Leaks. My only regret is not planning ahead and sourcing OEM Jaguar hose clamps. The ones I had to buy at my local Napa are not even close to the quality of the originals. These will get changed out when I replace the filters.

 

Looks great, I agree about clamps, I have probably ordered fifty of different types and dislike them all. Especially at the tank connection where space is tight. What size hose did you use for the returns?

 

MSG, where did you get your 12mm hose? I keep finding 12mm -1/2" which seems to me is going to be half inch hose like I have now.

 

Found it on Amazon. Hope this helps.

 

Excellent! Thank you much, did you find better hose clamps?