The EEC-IV has a failure mode with the cam sensor that will allow the car to start with it disabled. If the Crank Sensor is out, the engine can not start.
If you disconnect the cam sensor, you need to do a process of key on, crank, key off. Key on, crank, key off. You should run this cycle 5 times. During each of these times the EEC will "guess" at which cylinder it should fuel and try to start. If it never starts, then the problem isn't primarily the Cam sensor. (The cam sensor could be a secondary failure, but by not starting with it disconnected, you know that it isn't the main reason why the engine won't start)
Most no-start conditions really should be approached for the first thing of verifying fuel pressure. Make sure your fuel pump is working.
Once you verify fuel pressure, then check all the wiring connections. To the DIS, to the Crank Sensor, to the Cam Sensor, to the Coil Pack.
Below is a link to the DIS no start pinpoint tests from my former 89 tbird. Should be the same as the 90.
http://mnharms.com/tutorials/disnostart/
Make sure you check for any stored codes as well.