1982 Cadillac Deville car wont start

Have you determined that you are missing either fuel pressure, or injector pulse?

Here is a link that shows how to test your fuel system

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

You should have a test port in the lines heading to the throttle body, and it probably has a spin-on cap on it. Ideally, you would need a pressure gauge, for relatively low pressure, throttle body systems generally run 13-15 psi. As far as injector pulse, you would need an item called a noid light, or a high impedence powered test light. A general 12v test light wont work, and could damage the driver in the ECM. Disconnect an injector, plug the noid light into the connector, and crank. Light flash=pulse.

Check the fuel pump relay to see if it clicks when you crank the engine. It is located in position 8 under the dash in the relay center

So you have power to one side of theinjector plug? If so you may have lost the injector driver in the ECM. Since you have spark, the ECM is most likely getting the signal that the engine is turning, but it doesnt have the driver to trigger the injector (ground triggered). You can do a continuity test from the injector plug to the ECM, but I have a feeling it will be ok, and that the ECM is at fault. Good news is that those ECM's are very inexpensive and dont require programming, they are basically plug-and-play