My wife recently parked her 1998 Jaguar XJ8 Vanden Plas in the garage with the gas gauge showing below the " reserve" mark. We left town for a few days in another car, and the next time she tried to start her car, it would not start. We added 5 gal of gas to the tank and tried to start it again with no success. The car ran fine before this. I have checked the inertia switch and it is fine. I also checked the fuses for the fuel pump, etc. And they are also OK. The engine turns over with the starter, but will not start. I have not yet disconnected the fuel lines to check for fuel flow or checked the spark, as I am hoping there may be a simpler fix or check I can do. Any advice? Thank you.