I've had it! So freakin frustrated!
I am getting fumes that come in when the windows are open. Does not happen when it's just sitting there..ie.. In a garage with doors closed and smell no gas. I've disconnected the the the valve under the front tire, no difference. i've readjusted the rubber seal on the caps, checked the overflow tubes that are at the caps, checked all the gas line connections. For the longest time I was dealing with rust in the tanks so I was spilling in the trunk and I just thought that it was left over gas in trunk, but it's been months now and I still have fumes.
My girlfriend said she won't ride in it again until it's fixed, so now i'm a bit more frustrated.
ANY IDEAS!!!!

 

I have the same problem with a 1988 Vanden Blas, V12. I just bought the car and have not had a chance to investigate yet, but I am suspicious of the trunk area, where the fumes seem to be the worst. When the windows are opened, I believe I get a bit of negative pressure inside the cab, which may be drawing fumes in from the trunk. I also have a few holes under the driver's floor pan, so this could also be a problem? In any case, I plan to focus on the trunk for now; no obvious signs of gas leakage so I will have to take off the finish panels and I hope that will expose the gas tanks and associated piping.......perhaps the tanks are vented into the trunk?

 

That's an idea I haven't thought of. Yea, I know is negative pressure some how.
Thanks for the Idea.

 

there are 4 metal vent flaps below the rear windshield cowl (the openings are seen when you open the trunk lid), and two more behind the rear seat. (those can be seen when you remove the horizontal upholstery panel in the trunk).

these flaps hang by a piece of vinyl fabric rivetted to the body, and the factory glued squares of headliner fabric to each hanging flap to prevent metallic noise. When the headliner fabric comes unglued from the metal flap, (it does), the sealing "action" is defeated and this allows fumes to get in the cabin.

I would check them to confirm they are sealing.

NOTE: you do not specify if the fumes are gasoline fumes or exhaust fumes.

 

Thank you Jose for your post on the vent flaps; I will be checking that to see if the fumes stop. And, the fumes were gasoline. The odor was of "fresh" gasoline and it was so strong that we had to roll the windows up; seemed to clear up after that. I will have a look at the flaps. Thanks again!

 

Added. I had almost forgotten about their existance. There are two vents under the rear valence. Very susceptible to getting squashed! Mine were !!! A flat lever easily opened them with no apparent damage to the nice shiny paint.


In another forum, a past lister enlisted power ventilation to the boot of his Jaguars!!


Small blowers from defunct computers. Resistor needed. Value, ??? I've one in my "junk" tray for a someday project....


Carl

 

Interesting concept Carl. My boat had this system to vent fumes from the stern drive canopy, a handy measure to avoid bursting into flame during start up - never thought of it for the car!

 

The specific is in the title?
It ended up being the return line(?) in the trunk under the passenger panel into the tank was loose.
Trying to avoid this, that juat happened to my friend on sunday. Don't know how he survived this.

 

As a follow-up on this thread, I want to advise that I have discovered a physical leak in the return line, and the vapor line, in the area above the IRS cage, and below the trunk. I have the IRS down for brake rebuild, and, I turned the ignition key on, which fired up the fuel pump to pressurize the fuel supply line, and I had significant leak coming out a rotted fuel return line! And, the vapor recovery line was rotted in this area as well! Clearly, these leaks are contributors to my fuel fumes problem... there may be more problems, but I will fix these and see where things are. May have to get the IRS re-installed and do a test drive to be sure there are no more fumes. So, an area to focus on if you have fuel odor/fume problems.

 

This seems to be an ongoing and common problem with the older Jags, as I have now read many postings which touch on the subject. Well, I have now replaced the return lines and the vapour vent lines above the IRS, as part of my rear brake job project. Although much better, I still have gas fumes.
Re the venting system for the tanks, the carbon canister was removed by a previous owner. The line from the carbon canister to the tanks appears to be plugged. If it were not, I was thinking of simply removing the valve at the canister location (or piercing it with a drill bit), and vent to atmosphere. Since it is plugged, and rather than replace the line, I am thinking of drilling the tank fill pipes to vent to atmosphere, as has been suggested by others more experienced owners. If I do this, is there any concern with leaving the "vapour riser pipe" in the C-frame? i.e. might I still have fumes coming from these 2 units? I have pulled the interior finish back to have a look and the logistics of removing them appears complex i.e. they are inside the metal C-Frame. I have no idea how they would come out!
As an alternative to drilling the fill pipes, I was also thinking of simply venting each side into the rear wheel wells where the vent lines pass thru. I could also short circuit the tank vent line to avoid going thru the vapour riser pipe (except the vent from the filler pipe, which must be inside the c-frame?). Clear as mud?
What are your thoughts / suggestions? All comments appreciated, and welcome. I would love to get rid of these gas fumes!!!!!!
Regards,
Wayne

 

I have tried leaving the gas caps open and that did no good, so drilling the tank fill pipes would do no good in m case.
I am still trying to figure it out myself.

 

This helped, although I still have the issues now. Other people tell me about it. I just have grown immune to it guess.

 

my opinion is that you need to rebuild the entire evaporative fuel system to factory specs. Trying to outsmart Jaguar engineering always leads to problems, and that is what you are dealing with, someone already tried and failed, selling the car to you.

contact David at Everyday XJ he knows the entire system well since he dismantles these cars everyday. Start from scratch and rebuild it.

 

Blow some smoke from a homemade tester from the lowest pipe you have... then look for it in all the places.

My car had a bad hose from the tank filler cap upward to the vent pipe...fun to change but it resolved the fume problems.

 

Once again I think I might have found the culprit, but don't know how to fix it. At the gas cap, there is the little hose(old string wrapped and brittle), I expect that it is a vent or return. It is not connected(my fault from removing the gas tanks). I have no clue how to attach these hoses. tried all sorts of things and ended up chipping the paint, so I quit.
Anyone have ideas on how to get this old brittle hose on, or even where it goes so that I can replace it maybe?
Roger stated "My car had a bad hose from the tank filler cap upward to the vent pipe...fun to change but it resolved the fume problems." How does this route? Sounds like my issue as well. The hose is the old brittle string wrapped garbage and just falls apart at the cap.

 

This thread should help

https://www.jaguarforums.com/forum/x...l-leak-158240/


Cheers
DD

 

OMG! Pull the tanks again? Not gonna happen today....or tomorrow...

 

As you will note in the link added by Doug, I was able to replace that line to
the filler cap with the tank still in place.

I should have replaced all when the tanks were out but that is hindsight... doing it from the package tray area is a PITA but doable.

 

The last picture in the file looks like my dilemma. and I need to pull the tanks to get to it. I'll wait a bit and get it done when I have some time at home. I need to rebuild my rack and pinion first on the list. Maybe that will happen this week.
Thank you all for your help here. I'll give you an update when i get to it.