Fuel Tank Pressure

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Leon
Posts:51
Joined:Tue Aug 21, 2007 7:38 pm
Fuel Tank Pressure

Postby Leon » Fri Dec 28, 2007 11:22 pm

Hi all,can I just say thanks for all the info here,really useful and well run.
Ive a V12 coupe,VIN No 177873,1991 model pre facelift and is one of the Le Mans special editions.Bought the car in April this year and spent much time sorting the oil leaks on the cam covers,rear banjo fixings, (used "dowty" seals and modified bolts...works a treat) cooling system etc etc.Ive read many of the posts and got Kirby Palms book which is great...but,Im having a problem sorting the fuel tank over pressure after the car has been running for a while.Ive got the workshop cd for the car from JDHT but unfortunately has no detailed drawings of the system for tank venting.The drawings that I do have show the carbon canister and valve gear under the NSF wing....however after removing both inner wing covers this isnt the case.A drawing of the piping arrangement and equipment locations would be ideal,and any advice very welcome.


ptjs1

Member
Posts:3520
Joined:Thu Apr 27, 2006 7:14 pm
Location:Kent

Fuel Tank Pressure

Postby ptjs1 » Sat Dec 29, 2007 12:04 am

Leon,

Check for a kink in one of the overflow and expansion pipes in the boot that are connected to the tank. There is one that is prone to collapsing causing a pressure build-up in the tank.

Drop me an email and I'll try and email you the diagram

Paul

1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)

Leon
Posts:51
Joined:Tue Aug 21, 2007 7:38 pm

Fuel Tank Pressure

Postby Leon » Sat Dec 29, 2007 12:57 pm

Paul

Thanks for the info,I have sent you pm with email details.


Leon
Posts:51
Joined:Tue Aug 21, 2007 7:38 pm

Fuel Tank Pressure

Postby Leon » Sat Jan 05, 2008 3:45 pm

The Search continues.....

Ive checked the hoses in the boot area,all 3 x from the top of the main tank are ok not collapsed,they look like pretty good stuff actually.Ive found the vapour seperator in the OSR buttress and the 4th hose off this goes through into the rear seat area.Can anyone tell me where I might find the carbon canister?Ive checked both front wing areas and nothing found.Ive checked again the service and parts details on the cd I have and looked at the diagrams on the JDHT website and all these confirm its located in the front wings!
Does anyone know whether my system will be evaporative loss or non evaporative loss?And whether this makes a difference?

ps

Happy New Year to all :)


Leon
Posts:51
Joined:Tue Aug 21, 2007 7:38 pm

Fuel Tank Pressure

Postby Leon » Mon Jan 14, 2008 9:05 pm

The Search continues......part deux

Ive come to the conclusion that I haven`t got a carbon canister,is that for US spec only?The vapour hose from the vapour seperator goes into a pressure reducing valve as per item 8 JDHT diag http://www.jdht.com/webapp/wcs/stores/s ... gory=20221 can anyone tell me where the other end goes? I presume its onto one of the inlet manifolds.My JDHT cd drawings of the vapour pipework says "illustration to follow" :cry: and Im now stuck.Any additional drawings or info would be great


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Dimdip
Posts:48
Joined:Thu Oct 27, 2005 3:04 pm
Location:Odiham, Hants.

Fuel Tank Pressure

Postby Dimdip » Sat Apr 12, 2008 6:26 pm

Leon,

I'd like to offer help but can't. I've got the same problem ('92 5.3 Coupe) and have learnt to live with it.

Needless to say I'm watching with interest.............no pressure though (sic)

Ian

Leon
Posts:51
Joined:Tue Aug 21, 2007 7:38 pm

Fuel Tank Pressure

Postby Leon » Sat Apr 12, 2008 9:19 pm

It just so happens I have found the problem....well nearly.Thanks Dimdip Id forgot about this thread :oops:
I spoke to David Marks who was really helpful,apparently there are no emission controls of vapour from the tank on UK models,apart from a pressure reducing valve which also acts as a non return valve in case of a pressure reduction in the tank below atmospheric,which is sited OSR just behind the vapour seperator,Ive yet to test this but am convinced its gone.The other end of this valve is connected to a steel pipe beneath the car and exits around the area above the NSR drive shaft,its well hidden.There is a backup to the valve,the petrol filler cap itself which should release at a given pressure.I like you Dimdip am learning to live with it,I now drive around with the petrol cap barely screwed on to relieve the pressure.I will try to test this in the coming week and post accordingly,its another on the list unfortunately :(

irisphoto
Posts:75
Joined:Tue Aug 21, 2007 5:22 pm
Location:I.o.W
Contact:

Fuel Tank Pressure

Postby irisphoto » Sun Apr 13, 2008 5:19 pm

Hello is yours a 6L or a 5.3L? Phil

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Dimdip
Posts:48
Joined:Thu Oct 27, 2005 3:04 pm
Location:Odiham, Hants.

Fuel Tank Pressure

Postby Dimdip » Mon Apr 14, 2008 9:37 pm

Phil,

Mines a 5.3 as well.

Ian

2319tony2671
Posts:8
Joined:Wed Oct 08, 2008 12:10 am
Location:Waterloo, Ontario,Canada

Fuel Tank Pressure

Postby 2319tony2671 » Wed Jul 01, 2009 12:33 am

I am raising this issue again from a North American perspective. I live in Canada and own a 1989 XJ-S V 12. I have a petrol smell in the trunk, which I previosly listed. Having further investigated things I find that there was a recall in 1991 here in Canada which resuilted in a whole slew of new parts being installed at Jaguars expense. Todate I yet to determine if my vehicle was upgraded or not. However i obtained one of the service parts kits.
My question is, did these changes cure the problem? If not is there any one out there in NA who can advise me please before I go ahead and install the new parts


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