1991 Chevy Camaro Car Won't Start

If you can run the motor on starter fluid, then fuel delivery should be the issue. Possible fuel pressure regulator might be the reason there is no fuel being delivered to the injectors. Static pressure from the pump would be up to spec, as you can hear the pump running.

So that I am understanding correctly, the regulator could be bad even though it has correct pressure at key on and holds that pressure during crank? How long should the pump stay on after you turn the key off?

We went out to buy the fuel regulator and also got a tester for the spark plugs. Hooked it up and it is getting a weak spark. Forgot to mention before that we have also replaced the spark plugs, wires, and distributor as well. So not real sure what is causing the weak spark now.

Ok so we replaced the fuel regulator sensor. Still no start! Any other ideas?

If you had good pressure and it held, you didn't need a regulator.
You said you had weak spark so that is ignition. You also said it would start on starter fluid but quit when it ran out. Your weak spark and lack of fuel flow are probably coming from the same culprit.
Take out the ignition module (it is under the rotor in the distributor) Ad take it to an auto partsstore, they will check it for free. Have them run the test several times to get it good and warmed up. If it fails even once, replace the module. Now the important part. ONLY use an AC Delco module. If you use an after market (wells, GP, etc) you will be back for another one in a month or less
The reason that the no fuel condition is caused by the ignition module is that the computer is looking for a reference pulse from the module, then it will fire the injectors. No reference pulse, no fuel.