Had a question - I just had my '89 tank resealed (the tank is the model that doesn't have a fuel pump in the tank, but has a vent type thing on the top of the tank) that bumps out from the tank itself.

Since my tank is still out of the vehicle at the moment, i'd like to verify that nothing's blocked internally - is there a good way I can verify this, on this style tank?

I had some gas in it to test a few weeks back and it leaked out and created quite a mess. Even though I had only hooked up the lines and not actually started the vehicle up, I was surprised it had built up quite a bit of pressure from sitting overnight, as well. I checked the rochester valve up by the charcoal canister and that seemed to be operating properly..so I'd like to verify this configuration one more time, as leaking gas tanks over exhaust system lines aren't my favorite problem to deal with!

Pete

 

Pete,

Did you (or a vendor) use the liquid type sealer on the interior of the tank?

I choose not to use an interior liner because I was concerned about two things; a plugged line and improper adhesion/coverage on the interior baffling of the tank. I didn't want the lining peeling away after some time and creating a clogged feed/return line.

I'm assuming the leak a few weeks back may be due to the o-rings needing to be replaced, or the lines didn't seat properly to the tank. When I restored my tank, I replaced the o-rings on both lines and purchased new spring clips for the line-to-tank connections.

In regard to the presure build-up, should be typical to prevent tank collapse. There are two lines out of the top of the tank, one to the canister, the other (breather hose) to the fuel filler box assembly, does your tank look like this one:

Fuel Tank-Up To (V)629285 - Parts For XJ6 (2.9, 3.2, 3.6, 4.0) from (V)500001 to (V)667828 | Jaguar Classic Parts UK

One of the lines from the tank may have been covered by sealer, speculation on my part, but that's what I would check out.

Here's my restoration:

Jaguar Forums - Jaguar Enthusiasts Forum - Rob Evenson's Album: Fuel Tank Leak Repair and Rust Aversion Paint applied

Let us know what you discover, good luck.

 

Yes, that's the right tank....exactly..


I replaced those o rings and paid close attention to the sizing of the new rings, and the seating of the two pipes...they really 'snap' into place which allows the retaining rings to turn properly and lock the lines in place. So that seemed ok.


I had a local shop handle the sealing - they use a product called Red Kote. I'm sure there's 100 posts on the internet saying this is the best product in the world, and another 100 that says it's the worst...especially given the nature that the product, that it can be obtained by anyone and that doesn't guarantee a high level of standard prep for all of the applications that people are reviewing out there.


I have used Gas Tank renu products in the past, but it's an expensive route (more than my car cost, actually...) and in the past i've used it with with tanks that were fairly rough or in mounting locations that would require an engine pull to get to the tanks again....


This XJ6 wasn't that bad to pull the tank...not that I want to make tank swaps an ongoing maintenance task for unstable repairs, but I am concerned that the most likely leak area is right above an area where there is an exhaust pipe run. Since the tank is out of the car again, I thought I would examine this closely one more time - just to make sure (like you mentioned) these other vent pipes and such were clear.


Pete

 

Sounds like you have some experience under your belt.

If I was in your position, I'd pull the tank too and re-examine the bottom the tank for pin-holes. That spot on my tank hadn't actually broken through, but it was thin enough to cause seepage. It you look at my pics again, you can see how the bottom of the tank takes a real beating resting on the shelf. I had a moisture issue which exasperated the issue.

Take out the tank, seal the line feed tubes, place it on saw horses and put a few gallons of water in and let it sit. I speculate if there is a weak enough breach in the metal, the newly applied lining may have also been breached when the fuel was put in.

I applied a layer of fiberglass on the bottom of mine to distance the tank from the shelf, then applied several layers of rust aversion paint on top of the fiberglass. I think I spent about $140 total for all cleaning supplies, fiberglass, rust aversion paint and a quart of the lining material.

 

Still battling this. I have gas in the tank but it's not feeding the pump... I disconnect the fuel pump line and nothing comes out... I can blow some compressed air in the feed line and the pressure causes the air to come back out, but no gas. Now I'm trying to figure out what to do - if something is not connected internally, or broken internally, whatever it is, now I have a situation where I have a non-leaking tank that's also not allowing gas to come out of the tank. Good times

 

If your tank is the same as mine, (follow the link in the prior post) there are no internal components, other than the baffling, which has nothing to do with flow.

Have you removed the sending unit? It's a clear shot to see the bottom of the tank through the sending unit hole. There should be nothing obstructing flow....... unless there was an interior tank lining applied and it's worked its way loose.

 

Thanks Rob, I'll take another look... I'm going to do another test on the 'new' pump to make sure it's doing what it's supposed to do as well... Seems to run for a few seconds on ignition start and stop..but no gas ever makes it's way to the pump from the tank.


If I recall from the last time I looked in the tank through the sending unit area (months ago) there was a pipe inside that had to remain hooked up...perhaps this was for the vent at the top? When I looked at the two connections on the bottom of the tank (from outside the tank), it looked like they had some sort of plastic seat (for the two o ring connectors), and the tubes themselves would do a turn right after going into the tank. (These 'seats' were black, as I looked into each it wasn't just open tank area...


The saga continues... I wish someone had another tank option near me, or even aftermarket ones available like the Series III.... here I am in the Motor City I have to make a 2 hour drive to even look at another potentially rusty tank replacement option from a wrecker..heh. Might even go with a custom tank if this gets too crazy.. Though, that would make this project crazier than it already is! heh


Pete

 

OK, so I finally gave up and sacrificed my tank in the name of science. Actually I made a 4th trip to the shop that 'sealed' my tank and they were just as animate as ever that it was going to be fine and "all the lines are clear". Three of the times I went back it came back leaking, so I wasn't exactly holding my breath, especially given the fact that they did such a poor job in cleaning up their botched repairs.


Anyway, I filled it up and surprise - still no gas coming out. That was the last straw with this frustrating task - I then purged the tank and cut it open and here is what is inside an 1989 Jaguar XJ6 Fuel Tank...


As you can see, the Red Kote fuel tank sealant plugged up the baffle for the feed pickup and in one of the photos you can see the water I filled the tank with, couldn't even get into the middle cylinder area where the pickup screen exists. All in all, a big waste of time. As you can see, that center pickup area is still covered in a layer of rust, so I'm pretty sure they didn't do the proper necessary prep (as I expected) to dissolve any surface rust inside the tank, ironic as that section was the rust that was the primary concern for having the tank sealed.

Evidently Red Kote can be dissolved with Acetone, but at this point, I don't think this process is ideal for this tank style, at least not in the way this shop handled the process...and I had enough fun going back and forth and draining fuel tanks that I didn't need an afternoon filled with flushing a tank with acetone and hoping it got everything out while not igniting the acetone filled bucket in my driveway. it was just too thick for some of these areas and in the end just caused a big problem. Hopefully this helps someone with their project(s) down the road somehow...


Just for kicks I filled the tank with water and some stuff came out... but not much.....water level must have been high enough to reach over the baffle but still was partially blocked through that screen or tubing somehow...


There's quite a bit going on in this tank... not exactly the 'hole in the bottom with a hose connector' that some of the older tanks are...


Enjoy! Now, on to find a good tank...

 

Wow!!!

Sorry to hear of the prognosis on the tank. Too bad you couldn't get some satisfaction from the vendor, they didn't do you right.

 

hello,
i have some of the same problem, the petrol seems to have a partial obstruction, sometimes the engine stalls, or loose all power, and then gets normal.
the pump made a noise as it was cavitating,i replaced original pump,and when the pump was tested out of the car, there was no noise, but the new pump once on the car, makes noise again.
i have checked on rust in the tank, via the level sender hole, but there was , except a little part (put a telescopic stick with a magnet on it) when the engine runs, there are air bubbles coming in the fuel (under the baffle
Best regards
Michel

 

michel315,

Welcome to the forum. What model year is your vehicle, very important information? Though the XJ40 model run was but six years, many changes were made to delivery systems during that time. We need to know your model year in order to give you the best advice. The last six digits of the VIN is helpful too.

You should get a fuel pressure reading at the fuel rail (supply side) first before tearing things apart. This reading will tell you if your supply side is good back to the pump. From your description, I think your problem is after the fuel is induced into the fuel rail.

Regarding the bubbles, just a guess at this point, you may have issue with the emission control system inducing air back to the fuel tank. Remember, there is fuel feed and fuel return systems.

 

hello, thanks a lot for your reply, in fact the car is a XJ6,2.9 1988,but most of the parts as well as the fuel system is same as theXJ40. they made a 2.9engine, as those times over 3000cc, was 33% taxed.there is also a noise between the pump and the filter like a fluid that have bubbles in it, as well as vibration.when i start the engine it looks better but after a longer drive it get worser, then engine stalls and loose all power for a moment. i read that there could be a problem when the environmental temp, but here in Belgium now it's +- 18°C (+-65F) thanks again for the help, best regards Michel

 

michel315,

I still think you need to get a pressure reading at the fuel rail to ensure the pump is producing proper psi at the rail. The symptoms you describe could be attributed to other electronic components that monitor air/temp/fuel to the main ECU.

Another item you could check (though I doubt it's the cause) is to pull the fuel pump relay and read the voltage at the relay, or it could be the relay itself is sending erratic voltage to the pump. I don't know the expense for one in Belgium, but it shouldn't be too expensive and it never hurts to have a spare.

Ensure you have cleaned all ground points on the vehicle. These cars do not like dirty grounds and since ours are 25 years plus, a thorough house cleaning can be helpful in eradicating many electrical "gremlin" issues.

 

hello Rob, thanks for the information, in the meantime, i have drive the car on long distance, for about 1200 miles, and it seems going better.
it was better with a 100% filled tank, and now the noise is almost gone. i wonder if there is not a check valve between the tank and the pump, who was sticking, and made that cavitation noise, so hope this will be solved.
after that there was an exhaust seal blown, and the rubber bush on the left hand shock absorber is also "dead", but this is normal, as the car was stored for about 10 years. as i have owned à Tr3A and a triumph gloria (1935) i know what it means to own old cars, before they in a perfect state, but that's the fun to make those nice vehicles on the road, thanks again and keep you informed on the evolution, Michel (Belgium)