1999 xjr, I think I have fuel pump problem, car starts for only a second, sometimes will run a little. I pulled the fuel line off the filter, gas comes out just for a second then stops. checked the relays and replaced them with others of same kind and still same problem. then I jumped across the pins and the car runs and idles good although I didn't take it on the road.
I then jumped across one at a time and it ran on one and not on the other. does that mean bad fuel pump or should I do more testing?

 

As you know the XJR has 2 pumps. here is how they work:

1/when ignition is turned on, pump #2 energize for a few seconds to built up pressure then stop

2/ when starting/running engine, pump #1 is turned on

3/ above a certain rpm's pump #2 is turned on to supply extra fuel

4/ if an electrical problem is detected with pump #1, pump #2 take over pump #1 duty

 

ok so when I jumped across the one relay and it ran but didn't on the other that means I have a bad pump? sounds like the one that first builds up the pressure is working but not the other one right?

 

another question, if I remove the relay for pump #1 would pump #2 take over since it seems to be working? I tried and car doesn't idle just starts for a second then quits.

 

I am pretty sure ther is no fail over strategy. There is plenty of advice in the archives about tank removal and replacement. Its a PITA, but doable. Good luck. Bad way to spend a New Years day, huh?

 

Look at this thread: https://www.jaguarforums.com/forum/x...ed-help-49737/