1984 XJS Injectors not firing

Purchased as a non runner last September I have been a chef all my life and now I am 85yo I wanted to do something different the last owner had lots of people poking around in the engine compartment to no avail I have had it running but then when you turn it off It will not start again. I am at a loss at the moment I have done a lot of work replacing and renewing parts but this has rely got me.