Frederic, here is a link to a thread about a baffling no-start that Jag.Man experienced with his '94 VDP.
1994 Jaguar VDP No Spark - #185 by Jag.Man?
It is an interesting read when you have plenty of time (and a cold pint or two at hand) - it is 193 posts long! Spoiler alert: the faulty component was the ignition on relay. On the '94 models that relay is on the firewall in the engine bay. I believe on your '92 model it is on a ‘component panel’ under the right-side dashboard. The relay should be serviced by white/blue and brown wires.