1990 Ford Thunderbird Won't Start

I would just try and eliminate systems as much as possible. These suggestions are probably not how a professional would do it.

Pull a spark plug wire out of one of the cylinders, put a screw driver inside it, lay it across your exhaust manifold and making sure NOT TO TOUCH it, have someone crank the car and watch for a spark. If that works, it is probably not your electrical.
If it doesn't spark, look at your fuses firstly (I assume you already have) then try to trace it back from the spark plugs. My brother had super coupe that stopped running on him, it turned out to be a faulty coil pack.

You can also pull a rubber fuel line near the injector rail, have a friend turn the key to on, and make sure it is getting plenty of pressure. If so, it is probably not the fuel system.
If you have no pressure, again make sure all the fuses are good, check the fuel inertia switch in the trunk (driver side) and then check your fuel pump again. It sucks, but these do come dead from the factory sometimes.
Oh, one more interesting fact, I dropped my tank for the 4th time. When I put it back together, I pinched the rubber fuel line between the bottom of the car and the tank, everything appeared to be working but there was no pressure. I just had to take a bolt loose and reposition the hose and everything worked great.

If everything else is good, that would only leave your air intake, I am really not sure how to check this, I know some vehicles will not start without the MAS (mass air sensor) plugged in, so that may be going out. I am not sure how many sensors a super coupe has.

Good luck,
Ryan