I have a 1989 XJ6 Jaguar that will not start. The computer sys has been replaced a year ago. It turns over, It is gettiung gas, The plugs are firing, The timing is correct, replaced the pressure sensor.........Still will not start..Pls Help

Optional Information:
1989 Jaguar XJ6 6 CYL

Already Tried:
PLUGS, DIST CAP, WIRES, PRESSURE SENSOR, ROTER, WATER TEMP SEN,