What is wrong with my car?

1992 oldsmobile 98 with 3.8 not super charged wont start we have put a list of new parts on it new- ecm computer, crank sensor, cam sensor, coil pack and the flat part that it connects to, new relay, harmonic balancer, timing chair and gears we have checked the fuel pump pressure it holds 45 psi and still nothing. Please I have to have this car HELP. thank you