I hear bubbling from the fuel tank?
 

Jaguar xjr 1997

See page 80 for the fuel tank system you have

One way to tell is if you have only one square vapor condenser on the left side just froward of the left rear wheel or two , one on each left and right side

No jacking needed

http://www.jagrepair.com/images/Trai...20-%202000.pdf :icon_dance-disco:

I wasn't 100% sure this was an issue, as she seems to be fueling and running fine under load. Hey, the manual works for me though!