wat do i do its backfired 2 times in the last 5 month then it never did it again
well and hour ago i started my car and car barly started and i had to pump it to start it then it ran then car started shaking whats the problem

 

I would say your timing chain is going out. Chains are better than belts but they can still develop slack over time. It is also a pretty easy fix on the XJ a lil automotive knowledge is needed. But it can be done with a Chiltons or Haynes. or hell post up on here and we will walk you through it.

When timing it off the XJ will run like CRAP.