hard toguess - try to get it to an AutoZone or other auto parts store that can connect a Scanner and see if they get a Fault Code. It can besomething likethe throttle position sensor, or "throttle switch" or as simple as agummed intake.

go to this page so you can read about the different sensors that can cause an identical problem: It might help you understand why it is acting like that.

http://www.aa1car.com/library/2005/us80530.htm

My advice is to get it scanned, the car's computer willstore a Code that tells you what it is.

Jose

 

most likly u could have sucked some CRAP off the bottum of the tank. go buy "seafoam" it wil usually break up that crap u sucked up. or just go get an injector cleaning. cant hurt.

 

Sounds like you have the same problem as my wife... the inability to read a fuel guage I'm always on her never to let the tank go below 1/2 as it's very hard on an electric fuel pump to run on low levels as the pump actually cools from the fuel. As well if you run dry, you risk picking up the sediment invariably left on the tank bottom. Fuel system service on a regular basis is highly recomended. Also as I have learned, Jaguar recomends you burn premium for very specific reasons and well worth the few centsmore. I also add fuel conditioner ever three or four fills. This has made a world of difference to my cat. ... and as you say, You now have a Huge problem with your XJ.

 

it could just be your fuel filter. If you had a lot of crap (rust, dirt, etc.) resting on the bottom of your tank, if could have been thrust through the fuel line and clogged up your filter. I've had similar symptoms in an 86 sovereign that ended up being either 1) fuel filter, or 2) fuel pump. If it's the filter, it's a cheap, quick fix, so it couldn't hurt to try.
Good luck...