I just got a 1994 olds 88 from my brother that had been sitting a year. The car wouldn't stay running, did some searching check the Fuel Pressure Regulator and it was bad. I replaced the FPR on my car it started up( this took a minute) got all excited got this car running, so I decided to to fix the oil leak from the valve cover, change the Plugs and wire and change the 02 sensor super easy straight forward process got this done and now the car wont start.... Any idea'* on what could of happen? I am lost and know very little about these car'*.
The starting process
1. Turn the key on hear the fuel pump wait 5 seconds( I also check and fuel is getting into the fuel rail)
2. Start the car. It just cranks and doesn't even attempt to fire or sound like it wants to start.
Spark plug are NGK and the wire are Ac Delco Professional and a Bosch O2 Sensor I check the firing order 1,3,5 front 2,4,6 back passenger side to driver side and the coil are mark with which one goes where.

Any Help would be much appreciated.

Check to see if you are getting spark to each plug. If not spark, I would start with the crankshaft position sensor. If you have spark, try starting the engine while spraying engine starting fluid into the intake. If it starts with the fluid you likely need a new fuel pump.

Sounds good I will check when I get home. Thanks for the help.

Ok I am getting spark, and Fuel to the fuel rail. I can spray fuel through the intake tube and the motor will run soon as the fuel runs out the motor turns off. I have replace the fuel pump and sending unit, new fuel injectors, new pressure regulator . too me it seems like the injectors are not opening. I check and I am getting 12 volts to the injectors. I am at the limit of my skills and don't know what else to look for.

If the vehicle starts and runs with starter fluid, as long as you spray, the ignition system is ok....I prefer using carb cleaner....

What comes into question is fuel pressure or injector pulse.....

You say you have fuel to the rail, but you need to know what the actual pressure is with a pressure gage.....If fuel pressure is ok, then you need to see if you have injector pulse......You have power to the injectors, but you need to know if the ECM is pulsing the injector......a noid light attaches directly to an injector harness, and will flash during cranking....if it doesn't flash, then that is your problem.......

Fuel pressure should be 45 Psi? I can just hook a pressure gauge to the fuel rail right? I will check that and see if I can't find some one or get a loaner from autozone for the noid light. Thanks for the help.

What is the "Security" light doing in all of this?

Never pay attention. What should it do? when I first try to start the car should it come on or be on?

When you turn the key on, it should come on for a few seconds, and then go out. If it stays on, or is flashing, it could be the issue.