Didn't say if yours is a Hess & Eisenhardt convertible or not. Really though if the fuel vent is whooshing, doesn't matter, you have a problem either way (you may also hear occasional bangs coming from the boot while driving... this is your fuel tank going from pressurized to depressurized and is *not* good).

Here is a treatise on the subject of the fuel vent system. While it's specific to the H&E, the H&E additional complications involve the secondary fuel tank and pump, which make it more susceptible to problems with a dodgy fuel vent system. The overall vent system is common to all XJ-Ss of that era though.

Jaguar Fuel Problems

Here is my thread on troubleshooting the issue on my car with a few photos. Basically you need to disconnect the line going to the charcoal canister in front of the LH wheel well as a short term fix. WILL CAUSE FUEL VAPORS TO LEAK OUT INTO YOUR GARAGE. Immediately upon disconnecting mine I could see, hear, and smell the fuel vapor escaping from the now depressurized tank. As a long term fix, you can try replacing the Rochester valve. Others have also plugged up the end of the vent line with a metal disc and drilled a very tiny hole in it.

https://www.jaguarforums.com/forum/x...ization-77840/

Personally I would disconnect that line to the canister first and see if that makes your cabin and boot fuel vapor smells go away before tearing into the fuel tank and associated lines (although you may now have fuel vapor smells coming from the LH wheel well, they aren't in the cabin and you now know what the problem is!).

I just replaced mine last month. British Autowood in Florida, they do a turnaround in less then a month. They are running a small discount on XJ-S interior currently... all the wood trim for a bit under $500 including the cup holder conversion; they did an excellent job. Cupholders fit a 12 oz aluminum soda can like a sleeve, so that should give you an idea of what sort of cups it can hold.

Cheers,

- Will

 

Sorry, my 88 is a regular coupe. I stopped by my mechanics today and he's going to take it in next Thursday. I think we're going to pull the tank if he can't find a definitive cause without doing it. At that time I think we will update as many hoses and systems as possible. I found an oem pump from a defunct dealer sale ane figure it's as good a time as any.
I've got to tell you my gut says its going to be one of the two tank hole issues I've heard about. The spot weld or that pesky little screw that may be poking it.
Whatever it is, it worsened exponentially after I filled the tank. My guy says it could possibly be the weight of the fuel causing more weeping until it runs down lower.
Very frustrating!!!

 

The odd thing is I really don't have fuel smells in the cabin. Just the old classic interior smell!
I do happen to get a whif of fuel with the windows down and driving. Go figure! The engine has no fuel smell at all it's confined to the boot.

 

I had a fuel smell related to the evaporative vent system. It's a relatively simple system, but has a number of parts. I'll try to explain how it works on my 83 coupe. H&E's, pre-HE, convertibles, or later cars may be different.

Mine has a charcoal canister in front of the left front wheel with three vacuum valves, a line to the tank, a line to engine vacuum, a line from one of the vacuum valves to engine vacuum, and two lines to ported vacuum on the throttle bodies.

The tank vent line goes forward to the charcoal canister. There is a valve which keeps this tank vent line closed until vacuum is applied. Any accumulated tank pressure is fed to the canister when the car is started and vacuum opens this tank vacuum cutoff valve.

The canister has another line to inlet manifold vacuum. This line is closed until the two other vacuum valves are activated by ported vacuum on the throttle bodies, i.e., they open up as the throttle is opened.

When all the valves are opened, any residual vapor in the charcoal canister is pulled into the intake and burned. The flow rate appears to be metered, so it's not as if a sudden vacuum leak appears. The fuel cap has a one way valve to allow air to enter if the tank pressure falls below a certain level. The cap prevents fumes or pressure from bleeding to the atmosphere.

At idle, when the ported vacuum is zero, the two valves controlling engine vacuum to the canister are shut and the canister is only open to the tank.

When the car is shut off, all three valves are shut and the system is closed. All three valves are connected thru thermal vacuum switches so they don't operate until a specific temp is reached.

Apparently, as on mine, if the vacuum valves fail, the tank will build pressure. Fumes and possibly fuel will escape and you'll get a big odor. I had a big whoosh every time I opened the cap. Fixing the evap system completely eliminated the odors in the trunk, cabin, and engine compartment of my car.

 

Well, we've inspected everything short of the tank itself so my gut says its that pesky tank rivet rust. My mechanic said with the full tank being full, it probably caused enough pressure from the weight of the gas, to cause a stronger weep.
It looks as if the fuel venting system is good and no leaks from hoses.
And now that the fuel level is under 1/4 tank, the odor is much less.
So far, after driving almost everyday, I've had no issues with anything. Runs cool, electrical gremlins not rearing any heads,
Hope this is as bad as it gets!!!!

 

From Cerefice, RJ... 1987XJS Coupe in Califitnia.
Everyone is on the rigjt trsck with gas odors on our (US) trunks.
What we need is someone/some parts distributor to assemlbe and sell s KIT wiyh sll tje bits snd pieces mentioned in the string of emails.
Does ghst sound plausable to yo all?
If yes, lets make s list and hear dealer/ distributor suggestiond...

 

Hello, do you have an updated link to this information? Thanks.

 

can anyone tell me what the rivet on the right side under the fuel tank is connected to? i removed my fuel tank, repaired and custom cut some closed cell padding but knocked the rivet out trying to reduce the size to avoid future leaks. i would like to replace the rivet from above to have it smooth but cannot figure out what to push up from below. afraid it may require extensive removal of parts.
its a 1989 XJS Rouge coupe.
thanks,
chris

 

Had my car up on ramps for other work, noticed a disconnected vacuum hose to the charcoal canister/Rochester valve, reconnected and no more gas tank whooshing or gas smell in the trunk.

 

There is a huge moulded heat shield under the car above the rear axle, made out of moulded woody stuff. This is one of the fixing rivets of this heatshield I am pretty sure. You can probably forget about it!

Greg

 

you could fit a pressure release valve to vent through the floor.
I fitted one last year and never get a fat tank in a sun heated
workshop or disengaging filling station pumps since


Mocal Fuel Tank Pressure Relief Valve - In Line Fitting Motorsport/Rally/Racing | eBay

 

Fuel smell in the trunk and interior of the Series III and XJS originate from tiny cracks in the baffle spot welds on the exterior of the metal tank shells. The spot weld to tank skin fractures over time from internal pressure and fatigue. These cracks permit minute amounts of fuel to leak out, run down the exterior of the tank and collect in the fiber pads the tanks rest on. It gets worse oin warm weather when pressure build up inside the tanks when the fuel expands and gasses off. This was a well known issue in the '80s & early '90s that Jaguar UK did a lot of tap dancing on, claiming it was adhesive smell, leather, etc. ad nauseum. Owners would put objects in the trunk and find they reeked of gasoline later. The root cause was discoverd by the guys at Jaguar USA service. They put dye in the fuel, pressurised the tanks and then checked the outer skins with black light. They could see fuel weeping around the spot welds and running down the sides of the tanks. Although the cause was known, the issue never really got addressed once Ford bought the Company and moved on.

Naturally on vehicles this old other factors can arise, like aged & cracked hoses, rust, etc. The only real fix is to replace the tanks, the fiber pads they rest on and then air out the interior and trunk. Hope this helps.