Hello my friends,

First off- Just got my first XJ6 and I absolutely F%^& love the thing. I've barely driven it as since I bought it because it needed a bunch of things. It had been sitting for 10 years- 55K miles on it and someone just couldn't deal with it anymore. Anyway I have a maddening fun smell in in the car and hoping someone can help me. Its particularly prevalent under load. Its only INSIDE the car. The trunk doesn't smell of fuel and there are no leaks there. No leaks or smell in the engine bay either.
I became very familiar with the fuel system when I bought it:
Replaced both tanks
Replace both return valves in rear wells
New Senders
New Changeover valve
New Fuel Filter
Cleaned out Evap canister and replaced charcoal
Tested purge valve (works)
New Pressure Regulator

There are absolutely no leaks visible from outside. No smell or anything notable in the engine bay. The only thing I can think of is because its most noticeable while driving and under load that it has be related to fuel usage so its after the fuel pump or maybe evap system? Totally stumped.
Any help would be great. Thank you.

 

there are Fuel Vapor Filtering Canisters inside each C post, you will need to pull the inside black trim on each side of the rear parcel shelf.

do you get a "whoosshh" pressure release when you open the gas tank filler caps? This is caused by the pressure relief plastic valve located before the charcoal canister. You can remove it or push a 1/8" drill bit through it to break the membrane inside it. There are no side effects from doing this. The pressure in the tanks is relieved.

Behind the rear seat Back, there are fuel hoses entering the interior from the trunk, they are covered by black plastic covers held in place by black plastic pins. Remove the entire rear seat and then inspect those hoses. Wherever the smell leads you, that is where the vapor or leak is coming from.

 

Year and engine size would be helpful!

Assuming you have a Series III with the 4.2 fuel injected 6-cylinder.......


Fuel odors are very frustrating. They don't behave like you'd expect. And it doesn't have to be drippy leak to make a big smell. An ooooze will d it.

At the very front of the cylinder head below the dome shaped breather cover, is a fuel return pipe with a 2" long section or rubber hose. It's probably invisible under a layer of gunk. The rubber section can leak. Replace it !

Also check the hoses at the fuel cooler, approximately above the fuel cooler. For that matter, just replace all the fuel hoses in the engine bay and be done with it.

In the roof C-pillars are fuel condensation canisters which can rust out. Put your nose in that area. A leak in these canisters would give a particularly strong smell in the cabin.

Carefully check the under body pipes. There are several. The odor from a leak would travel upward into the cabin.

After another cuppa coffee I may have more.

Cheers
DD

 

Thanks Jose- I forgot to mention- I already poked the membrane leading to canister so thanks for that. No woosh. BUT I think you are right- next step would be the back seat as it feels like its in the cabin. If I were to get to the C-Pillar Canisters- what am I looking for there?

 

Thanks- Yep 4.2. I did look at the front area of the engine- looks good but will prob do as you say and replace all that. I'm thinking rear might be my first bet as it feel like its in the cabin. Totally understand what you mean by underneath...will have to get there. Do they still make those canisters in the C-pillar? Likely not.....

 

 

Thanks Jose-- I've seen this diagram its a good one. I guess what I mean is when I see. those c-pillar evap cans- is it going to be apparent as to what I find as far as fuel issue? Like just looking for disconnected stuff or is there some other thing I should be doing up there. Don't suppose replacing these would make a difference.

 

ok, you are looking for a loose hose clamp and/or a torn hose. Ideally with a "sniffer" tool if such tool exists. No smoking near that area.

Maybe Doug knows what could be used. I have no knowledge of anyone replacing these fuel vapor accumulators, I don't even know how they got them in there. All I know is that there is a hose coming down from them and it Vents and connects somewhere, maybe to a "T" that goes to the charcoal canister.

Those fuel hoses inside the car last a long time. There must be a pinhole in one of them that is causing the smell. You might drive the car after removing the rear seat with someone in the back, a cat will tell you inmediately where the vapor comes out of. Cats are expert sniffers. They pinpoint the source right away.

 

LOL- Perfection. I will definitely do that. Makes total sense. I don't have a cat and I don't smoke....hmmmmm.....I can find a fluffer but not sniffer lol.
Thanks for you help...will circle back with results.

 

Has the car still got the wiggly rear exhaust pipes ? These were installed by Jaguar very early on to counter complaints of fuel smells in the cabin, particularly the rear. The original 1968 pipes were straight, and apparently the air flow cause some forwards flow that somehow was picked up and entered the car.

 

Thank you no. Pipes are brand new. Don't think that's the issue. But interesting!

 

Do you have a low pressure smoke tester? Go from the pressure relief valve towards the tanks with a 12 volt air pump designed for bicycles. This works best with both tanks low on fuel. 5 to 10 PSI is all you need and a spray bottle of soapy water. Remove trim where ever you feel needed. Spray around both flaps, pipework and such. Pressurize and watch for bubbles. Or you can purchase a inexpensive smoke tester and watch for the smoke.

Thank you

Larry Louton

 

Smoke pressure tester Ebay item#
273645507315 I use this tool to leak test exhaust and intake manifolds all the time, never misses a leak unless there isn't one.


Larry Louton

 

UPDATE: I pulled the seat for this project and to replace my headliner and while loosening the trim around the reading light at C-pllar- I DEFINITELY fount my gas smell. Going to pull the black trim and see what is going on there. Stay tuned.

 

excellent! what did you find exactly?

 

Thanks Jose. Well the canister is small right? like a small flask. I can smell the fumes in the C-pillar but don't see any holes or anything. It could be the canister itself. You can't even access it. is there any way you can choke those cans off and vent elsewhere? How would you even get to it?

 

if anyone has messed with those canisters, is David of Everyday XJ

he is our source for good used parts for these cars.

go to his website and contact David to see what he can tell you about the canisters.

 

Ok thanks....do you even know what it looks like. The diagram has them as round cylindrical and the one I see is shaped like a flask

 

Found it- It is a flask like unit. See pic. Wondering if I could repipe this to the outside......

 

To me it would be best to find the source and fix it.