89 Lemans 2.0 L, no gas when cranking.

Hi, I have power to the fuel pump for a few seconds, then no power. Relay module clicks(can feel it click off when holding finger on relay and keying ignition). I had replaced the relay with new unit, no improvement. Took off injector and keyed ignition, gas flows. Power to injector is 10-12 volts when turning over or just keyed on. I was driving when it lost fuel delivery, no noticeable problems to that point. Have 2nd identical parts car, which did run till it was parked due to extreme rust. I tried that injector in the other car and still didn't work. So the gas flows with the injector out, there's power to the injector-but it won't spray when keyed? Is this a pressure regulator problem? Not my day, help!