From time to time, I've had this "no start" problem and this is what I've found works for me. I'll take the key out of the ign. then put it back in, turn the key to the almost full on, just shy of starting, turn it off. I'll do this three complete times, then remove the key, hit the lock button on the key fob, then hit the unlock button, then insert the key and it starts. So far, this has worked 99 percent of the time. When this hasn't worked, I'll do the off on thing as above, and wait a good three or four minutes. I have no clue why it works, don't really care as long as it continues to work. Give it a try...

 

I'm having the issue right now as well. (Video link below). It just cranks - I need to pull codes, check fuel, check spark, and so on.

Question - does the Jag have a security anti-theft built into the key? I.e. you need the chipped key and it enters a keyring on the ignition to complete the circuit? That could cause a no-start like Curley.