Could someone tell me what this part is?
I get a slow, but steady gasoline leak that drips on the engine block (valve cover), and it's way too close to the exaust for comfort....
Thanks!

 

Well, I was able to identify the part calling up Motorcars LTD.
It's a Fuel Pressure Regulator, and what what I found out so far, there are no o-ring replacements for it. You have to buy a whole new part... ~$200....
Has anybody else ran into this issue, and maybe was able to match oring from some other vehicle, etc?

 

My experience has been that on XJ8 internet parts, or even Autozone or Advance Auto parts, the exact replacement part price used on the XJ8 or the Lincoln (usually) is the same. That includes secondary tensioners. Now, as to the Jag parts guys, they usually get a premium, but they have many more parts.
I would take it apart, figure out what is leaking, and then if it is an O-ring, (not sure if there is on in there) go get a viton or other gasoline rated o-ring that matches at many hardware or auto parts stores. Usually less that $2.00.

 

That's what I was thinking. I'll take the thing apart, take the o-rings to Autozone and see if they can match something. Im sure they will.. Here is the pic of part with rings...

 

Well, went to Autozone, and they had o-rings pictured in their system, but none were available for individual sale. The guy told me to contact the Jag dealer. Well, I told him I already did and they dont sell o-ring kits alone, and the "cheapest" fix was getting a whole new regulator with new o-rings ($200)..... Hmm, Ace Harware to the rescue... $0.89 oring, that's as close to the one I took out as possible... Had to use some cooking oil to help it fit back in the regulator housing. Started the car, let it run for 10min, dry as a bone.... Whoo hooo.... Now, this o-ring is most likely not rated for dealing with gasoline and eventually (a few months) will have to be replaced, but for right now, spending less than $1 for a $200 "fix", feels preeeetty damn good...

 

Hahahaha....good for you....keep an eye on it but it'll probably be fine for quite a while...it's a seal, not an immersed part so the actual exposure to gasoline will be minimal IMHO.