My jaguar always has a strong fuel odor in the trunk but no fuel leaks. Did this car have two charcoal canisters for fuel odor, one in the trunk and on in the engine compartment? Do they have a system to vent out the vapors in the trunk? If I lit a match or a spark from the battery I think there would be an explosion. The engine compartment is really has a strong gas odor I thought the car was running rich. Any Ideas?

First of all, there’s a very specific ratio that you need to have to combust these fumes. If you have too little or too much, it will not combust. There’s a Mythbusters episode where they do an excellent job explaining it.

Secondly, there is a charcoal canister for pressure relief, but it is located in front of your drivers side tire. (On LHD vehicles)

Your Rochester valve may have failed?

If you haven’t already, change EVERY fuel and vapor hose on the vehicle to Gates Barricade ( or other low permeation) hose. Fuel leaks result in fires, and there have been lots of XJS engine fires. Also, check the gas cap, another common leak point.

If you were looking for an actual drippy leak you may not find one. In the small confines of the trunk just a tiny ooooze will eave behind a big odor.

Agree on changing hoses but I prefer J1527 Marine hose

Cheers
DD

I forgot to add that you'll have to remove and clean the trunk carpeting to get rid of the odor....after the source of the smell is located. The carpet holds the smell. I threw mine in the bathtub with a generous dollop of Simple Green.

And.....the tank itself may have tiny leaks at the bottom. No way to verify without pulling the tank ...which it not a pleasure cruise.

Cheers
DD

Is there a drawing showing the hoses in the trunk and where they terminate. I know I read about a charcoal canister in the trunk I think it was next to the tire. Any ideas where to get a drawing with the locations and part numbers for the two canisters?

Is there a drawing showing the hoses in the trunk and where they terminate. I know I read about a charcoal canister in the trunk I think it was next to the tire. Any ideas where to get a drawing with the locations and part numbers for the two canisters?

I like the fluoropolymer lined SAE J30R9 fuel injection hose.

Can't remember if it was Gates or Goodyear I used, but it was/is awesome stuff. Blue teflon liner inside, and not bulky in diameter. Thin, flexible and high pressure rated.

Doug

The charcoal cannister is in the engine bay. The hoses in the boot are illustrated here:
https://parts.jaguarlandroverclassic.../brand/jaguar/
undercar
here:
https://parts.jaguarlandroverclassic.co
m/parts/index/part/id/278.900.1478.4930.21882/brand/jaguar/
in the trunk at the start of the breatehr piping
here
https://parts.jaguarlandroverclassic.../brand/jaguar/
Some of the tank piping
here:
https://parts.jaguarlandroverclassic.../brand/jaguar/
surge tank under the battery,
and here:
https://parts.jaguarlandroverclassic.../brand/jaguar/
Fuel pump and filter.

Now, with all the smell throughout the system that you have, it would be very unwise to start the car at all until the entire system is renewed, including the engine bay flexible hoses and the injector hoses. You may also need to make up or buy a fuel injector harness. All this work is a time consuming, but not expensive job. If you decide to go ahead do post again and loads of people will be able to help with the actual way to go about things.

My mistake. Please disregard my previous post. I should have realized you had the v12 before I responded.

I found a large black rectangular box under the bonnet, fuses and relays on front left side of the engine compartment wall. I have not removed any parts to get to the unit and look at it. I have not seen this unit on my drawings. Is there a drawing that shows the unit to get a part number and replace the charcoal unit? I also see that there was a recall on the fuel system gasoline storage tank assembly causing excessive fuel vapor pressure in the trunk and to install a revised fuel purge system to eliminate excessive vapor pressure build-up. Are there any drawing showing the original system and the new system to confirm that the recall work was completed on my car?

You might find the original recall documents here:

JagRepair.com - Jaguar Repair Information Resource

The parts catalog illustrations are often helpful

https://parts.jaguarlandroverclassic.../brand/jaguar/

Cheers
DD

Last year I changed out every rubber fuel hose in the engine compartment and in the boot on the fuel tank. Also replaced the gaskets on the fuel sender and the one on the header tank. I also have drilled a small hole 1/16" in the gas gap and used a small brass fitting with a small hose and routed it down the drain in the fuel cap door area. The fitting and hose are from model aircraft retract gear system and are tiny, but it's just a vent. I used to get a "woosh" sound when removing the gas cap. Obviously there was a pressure build up in the tank going on. Having done all that I am happy to report that the gas smells that used to bother me are no longer present.
Just to add this- My car does have paperwork relating to the recall on the gas tank.

Does anyone have a drawing that lists the sizes of hoses and fittings? The parts catalogs have jaguar part numbers but does not provide all of the information regarding the specification and sizes of the material. Looking in the engine compartment there are several different ID, OD and thickness of piping inside the car.

I had similar issues. My post about it is somewhere buried in past... but- The vent from the top right side of the gas tank, goes up to a small canister- tucked up in right rear fender, its only about 3-4" tall, and sits higher than the top of the fuel tank.... and it is a real pain to get to... that goes to a vent line, that runs all the way up to in front of the front left tire- look in front of the front left tire. There is a canister there, its about 1/2 the size of a football... american not soccer..;-).... Mine was plugged up- so the tank was not venting. The fuel tank is steel, and very prone to rust and pin-hole leaks. That is what mine had. There is also a long (700 page) article on rebuilding XJS- and in it- is a section on the fuel tank. Sorry, I am not good at linking past articles, or I would attach it here. I think Greg or Grant put it on my post.
I went and got an aluminum tank made. It was just under $1,600... and I no longer have to worry about pin-hole leaks.

Ok... sorry, I don't know how to link... but... My post on my fuel smell and tank... is titled 'Jag gas tank vents' and last post on it was 12-26-2023... if you go back to look at it...

My 94 had the same issue. It turned out the sending unit was leaking. Wiggle the connection and see if a drop off gas comes out.

Does anyone have the sizes and quantity of material for the fuel lines and the vapor recovery system tubing, standard bent parts (90*, T's, Y's, etc.)? I have contacted a major Jaguar parts supplier and they do not have the information or specifications of the tubing or fittings. I am replacing all of the filters, valves, tubing and fitting for the fuel and vapor systems with Gates. Gates specifications and black fittings are rated for this use. The white fittings that are sold for fuel systems are typically not of the same quality as the black Gates and other quality tubing manufacturers use for fuel, heat, sunlight etc. I will probably be forced to use the Jaguar specialty bent tubing parts. I don't know what I am going to do with the charcoal canister yet, I may put some charcoal briquettes in the can (non match light) Thank you all for all the great Ideas.

Cheapest, easiest and quickest is probably to start by replacing all of your trunk's fuel lines including fuel return ones located up behind the lid hinges.
A good chance they've never been replaced in last 38 years and became porous, hard and brittle.
If this doesn't help then, yes, fuel pump and then tank.