I have an engine that is surging at approx. 1,500rpm with a very light throttle when cold (lean mixture) and a fuel tank that is noisy/"oil canning".
I have removed the fuel cap as suggested previously and this "fixes" the noisy tank.
I have checked for vacuum leaks and found none, and now removed the emission control unit from under the left front guard.
All hoses have been checked for blockages, none found. The elect switch checked for operation, OK.
The large canister checked for blockages. OK.
The small round cylinder P/n 1X43-9S446-BB is a bit if a worry, I can see through it, (through the pipe ends), it does not rattle or seem heavy, in other words its empty. (Now why would Jaguar use a useless empty cylinder?)
I had a look on Ebay and this part is described as a vacuum valve and priced at some 30UK Pd ($60 approx.). a lot of $ for an empty cyld.
Also I cannot work out how the fuel tank can pressurise/vacuum when the tank vent pipe connects to a "T" junction at the canister and the canister is vented under the guard.
Questions :- What does this plastic cylinder really do?
Is there a description of this and its use?
Why would the tank "oil can" with the above mentioned venting?
Is there a reference/diagram of the system?
Has anyone else had this problem and overcome it?
Cheers, Mike

 

This is from the 2003 shop manual - it's over my head but may help.

 

Sounds like trouble with the fuel tank vent valve on top of the tank. It's all described in the pdf that Clyons posted, in the section titled Operation of On-board Refuelling Vapor Recovery.

 

Thanks guys, The info from Clyons will help a bit, and as he indicates it is complicated.
It appears you need to be a tech wizard with a special machine that goes "Ping".
Thanks Astromorg, I'll have a look-see at the tank end.
Merry Christmas to all.
Mike

 

Guys, did Ferdie or anyone else manage to dicover what the plastic canister is for? My 2003 went though the same trials last year when the gas tank cracked and dumped 1/2 tank of petrol into the spare wheel well. The tank imploded, not 'exploded'!
I had another tank fitted but the 'tin-canning' noise still continued so I am very apprehensive to drive it now. The guys who fitted the tank also changed the purge valve, although they fitted the wrong one. Whilst I was fitting the correct one, I too wondered what this empty plastic cannister was for and if it had anything to do with the on-going problem. The EVAP system doesn't seem to make sense because the cannisters don't appear to be connected to anything. The system is not the same as is described in Clyons except from the Manaul. Any further ideas??

 

JA Mark... the US and UK Evaporative Systems are different!

You need to get into this workshop manual from Jagrepair.com

http://www.jagrepair.com/images/Auto...p%20Manual.pdf

The Contents List is opened with the 3 bar icon, top left

Then navigate to Section 303-13 for diagrams and an explanation for how it all should work. Good Luck