What about replacing fuel pipes with hoses altogether? Those pipes leaving the trunk into the silencer box (as I understand it is called) do look rusty. Can’t I replace the full pipe + hose by just a hose?
If I look at the picture that @Aristides posted of his boot, it seems he did just that? Can’t see any remaining pipes.
Thanks for all the great advice, my knowledge is vastly improving!
Stefan
OK, Your validating documentation to that effect is?
In a message dated 2/26/2023 3:28:37 AM Eastern Standard Time, noreply@jag-lovers.com writes:
The handbook.
I don’t see what you’re seeing?
Hi Stefan,
Neither you nor I have the engineering data to say whether you may replace a metal pipe with a hose. To do so you would need to fully analyze the risk verses gains along with safety considerations. Jaguar engineered the system, spent a lot of time and money to make it operate efficiently and SAFELY. To that point a rubber hose may not be able to withstand the rigors of daily environmental operations as a metal pipe would. If it were me and I found rusty metal fuel lines I would fabricate new ones. Keeping like for like would be, in my opinion, a safer bet. Bring back to factory OEM as close as possible. Any time you vary from “original” you become experimental. If the experiment works out - Great. If not, what was gained (or lost)? There are certain aspects of making upgrades, such as a better ignition system, but safety critical items such metal fuel lines, I would consider the possible outcomes of such a venture.
Again, I’d start by replacing those two hoses plus the clamps. You mentioned you have an electronic sniffer. Do you get fuel vapor hits on other hose/pipe locations? Your progress will probably be slow, dealing with years of operational use, finding multiple problems (leaks) and fixing them will be the chore. Good luck and Good hunting.
Hope some of this makes sense. One of the reasons I’m such a stickler for keeping (mostly) OEM. I learned as a Test Pilot if you don’t have to go there — DON"T.
Happy Trails,
Dick
In a message dated 2/26/2023 3:51:40 AM Eastern Standard Time, noreply@jag-lovers.com writes:
OK David, Since I don’t have a Series 3 XJ sedan nor that handbook would you please educate me on what Jaguar says? I love to learn new, updated information. Even though the manufacturer contends XXXX it may not be totally true. That was the case with my John Deere lawn tractor. Fuel lines were purported to be E10 compatible. They were NOT! E10 detoriated the tank-to-engine hose inside. When the engines vacuum operated fuel pump pulled fuel the hose inner lining would collapse resulting in no fuel flow. That took forever to figure out!!! Once that hose was replaced with Marine Grade hose the problem was solved.
Never to old to learn so please, what does the Jaguar Operators Manual say?
Thanks for the update,
Happy Trails,
Dick
In a message dated 2/26/2023 8:01:08 AM Eastern Standard Time, noreply@jag-lovers.com writes:
I would take a picture but the manual is not here. It’s in there. This will do:
Earlier jags will work but the cork parts will suffer and hoses and diaphragms should be renewed with newer (compatible) pieces either way. I run E10, no issues.
Hi David,
Not doubting your word but seeing a source document is gold to me. I’ve owned numerous Jaguars to include a 1976 XJ6 sedan and a later XJ12 sedan. Both cars were amazing to drive and easy to work on. That was when the styling was Classic Jaguar IMHO.
Enjoy a Stuttgarter Hofbräu while you work!!! LOL
Cheers,
Dick
In a message dated 2/26/2023 8:33:56 AM Eastern Standard Time, noreply@jag-lovers.com writes:
Series III Handbook
Publication AKM4177 Edition 7
©Jaguar Cars Ltd 1983
Gasahol, a mixture of unleaded gasoline and ethanol (grain alcohol), is available in some areas. You may use gasohol in your vehicle if it is no more than 10% ethanol
We don’t know if Jaguar selected materials (hoses in this case) which were specifically E10 tolerant or, more likely, looked at existing materials and decided there wouldn’t be a problem. In any case, E10 is clearly called out as being acceptable; there was no admonition against it.
I seriously doubt that any car manufacturer in the 1980s was considering how well their fuel hoses would be holding up 35-40 years down the road.
Stiil, though, the original hoses hold up amazingly well, it seems. Jaguar was apparently using high grade stuff here…and the environment (unlike engine bay hoses) is not harsh.
As for E10 in general, well, experiences vary greatly. I’m convinced that other variables are in play besides the mere presence or absence of ethanol. Personally I’ve never had a problem with it after 20+ years.
Cheers
DD
Interesting what comes up on an Internet search.
https://check-vehicle-compatibility-e10-petrol.service.gov.uk/manufacturer/Jaguar
I take this article/site is from the UK Government?
Series 3 XJ sedans (6 & 12) were manufactured from 1980 to 1987 according to reference sources.
Doug makes a good point; 30-40 year old hoses…really how good are they? From an outward appearance they look fine but internally??? Cheap insurance. Change them and use proper fuel hose clamps.
Interesting facts and lots of personal opinions regarding Ethanol laced fuel. E5 or E10 is in such vast usage worldwide so cars manufactured after 1992 are mandated to comply with E10 fuel standards Any car made before… Well… just words on paper?
The goal of most Jaguar Enthusiast is to return the car to a safe, enjoyable mode of transportation. Regular maintenance and replacement of tired components is paramount to that end. Would one consider 40 year old spark plugs up to the challenge?
Thanks Doug for the reference. Good to know. Wonder if that was just a blanket “Cover your A$$” statement or had they done exhaustive testing to come to that conclusion. Only Jaguar will ever know… Ha Ha
Happy Trails,
Dick
In a message dated 2/26/2023 10:08:24 AM Eastern Standard Time, noreply@jag-lovers.com writes:
Yeah, we can only speculate. Exhaustive testing? I really doubt it.
If Jaguar felt that E10 was a problem I think it’s a fair guess that they’d source compatible materials or admonish owners not to use it. I dunno about the former… but they clearly didn’t do the latter.
But I also think it’s a fair guess that nobody at Jaguar in 1983 was worried about our evaluation of their fuel hoses in 2023 
It’s all rather academic. No car hobbyist I know has an expectation that rubber fuel lines should or would last forever.
I’ll add that, personally, I am not “pro” E10. Quite the contrary, actually. However, I think the anti-E10 sentiment is so pervasive and so reflexive that it is being incorrectly or unfairly blamed for problems. It has become a very convenient whipping post.
Cheers
DD
I guess most people are driving E5 (98) petrol? I am in any case. It is more expensive though…
Not quite true
Precisely!
I used to drive on E10 95 all the time. Light pinking on hot summer days. My block was resurfaced, 8.7 (standard) compression and the usual timing. I did not have any related problems in my 5 years of ownership, and the lines in the boot were original. Not the ones under the bonnet of course?
E10 and its derivatives would fill a large book on “Pro’s” and “Con’s”. As a long time (50+ years) Jaguar enthusiast I am always leary of deviating from “factory”. This makes buying aftermarket parts a real challenge, especially when that’s all that is available. I’m sorry but not the same with numerous examples to back that up!
I, too, am a skeptic of a fuel that has modified octane rating, a lower BTU output resulting in lower mpg’s plus affecting components in unforeseen ways. Here’s an article that gives quite a bit of explanation of the various ratings and, in particular, an Alcohol warning for vehicles made before 1986.
Back to eliminating a boot (trunk) gas smell. The smell can only come from a leak, seep, or weeping fitting or hose. A real PITA to sort but the car came from the factory without such offending fumes and it can be returned to that state. It just takes patience, Sherlock Homes detective work and quality replacements.
Stefan. is your car roadworthy now? Does it have a current MOT or TUV?
Keep at it. You will eventually beat the dreaded “smell” and return to Happy Motoring.
Happy Trails,
Dick
In a message dated 2/26/2023 1:29:35 PM Eastern Standard Time, noreply@jag-lovers.com writes:
A growing problem for many in the old car hobby. Low grade replacement parts. And, with Jaguar at least, ordering Jaguar-packaged/branded parts no longer assures you a higher quality part. Jaguar is buying from other vendors/suppliers/manufacturers and these parts are clearly not true “OEM”.
Right !
One problem, I think, as a tendency to look only for an actual drippy leak. In the confines of the trunk even a tiny oooze, or invisible permeation thru a hose, can result in a very big odor.
Historically this has been a bigger problem, and a more common one, for XJS owners. Series III cars, it seems, were not quite so much of a problem. By now, though, I reckon age is taking its toll.
Using the marine grade hose is what did the trick in my case.
Cheers
DD
Even new S1 had that issue according to press reports! There’s a reason most cars have the fuel pumps either in the tank or on the outside. The vents in the spare wheel floor are a later feature. I have given up - for now!
Gates barricade is supposed to be good - the valves, pump and filter shouldn’t leak anything but that’s the theory. Taping up the entries from the tanks could be a start, to locate the source better.
Good to know info Doug. When you replaced hoses did you refit with OEM or new Fuel Hose clamps or worm gear clamps?
Happy Trails,
Dick
In a message dated 2/26/2023 5:20:29 PM Eastern Standard Time, noreply@jag-lovers.com writes:
Hmmmm. You’re over-taxing my memory!
Cheers
DD
Not a good idea.
Fuel hose so close to the exhaust is dangerous because of the heat. That’s why that metal segment is there.
The pipe is there, it’s just that I mounted the hose flush to the grommet/body.
Ans as Dick said, use fuel hose clamps and not worm screw clamps.
I use E10 on my Jag and have no problem whatsoever.
Nevertheless, I have changed all hoses with ethanol compatible, as well as the fuel pump with a later version.
Both the original fuel pump and Tank to Pump hoses were leaking but don’t know if the cause was the E10 or just that they were 30 years old.