XJS Start Problem

Post being stored for the 1st time will not refire. Fuel is active on rail but seems to lack spark. 89 XJS V12

If this car has a Marelli ignition, the first thing to do is confirm that you have spark, and ALSO confirm that the injectors are clicking. If you have NEITHER spark nor injector click, the most likely cause is the crank position sensor at the front of the engine, or the engine speed sensor at the back. There are many posts on these and the associated wiring, a flaw in either will prevent injectors from clicking and plugs from firing.

Thanks for the tips—She has always started and was stored out of
weather…

There are more than a few possibilities, but what I have described above is a five minute check that will quickly tell you if you should focus on the sensors, or elsewhere.

A few weeks ago, I almost came here to make the same post about not starting after sitting.
I had my 83 in the garage since December and couldn’t get the engine to fire. After replacing the battery(warranty) and charging the new one, I finally got it started.

These engines seem to prefer hot batteries