1990 Jaguar Sovereign starting after sitting overnight

Engine Mechanical problem
1990 Jaguar Sovereign 6 cyl Two Wheel Drive Automatic

my car wont start in the morning for about 15 - 20 trys then it starts right off the rest of the day and runs great, the fuel filter was pluged and I changed it but it did'nt help, the car was in storage all winter and when I took it out it started right off after 6 mo.
there is no voltage to the pump untill the start position of the ignition switch. Do you think it's the ignition switch or the check valve in the pump or the pump not holding fuel up in the fuel rail over night.