We went through this in some detail a while back, not to cover the same ground over and over again when you get a chance flick through this post, https://www.jaguarforums.com/forum/x...-spark-118292/
We had diagrams and pictures of where everything went. He ended up with a different problem that you describe but the logic is still the same.
As far as testing spark, buy yourself one of these
Automotive Spark Tester Coil Leads Ignition Indicator Testing Spark Plugs Tool | eBay
Good luck!