My engine stalled fuel pressure is at 49-50 lbs for two to three seconds

My car was towed to my house after it quit running. I checked for fuel pump operation and found approx. 12 volts on the green wire on fuel pump unit. I checked for ground, good ground on cable, and when I put key on, I can hear the fuel pump run for two to three seconds. When I crank over engine the fuel pump green cable has battery voltage. The vehicle does not have a fuel regulator on the injector assembly. Therefore, I checked for fuel pressure with a tester. With key on, the fuel pressure is at 49-50 lbs for two to three seconds. Then, with key on, it stays at 45-47 lbs. I add fuel to the intake and the vehicle starts momentarily. I noticed that the remote key will not lock doors as before the vehicle quit running. I checked for voltage on the power wire on injector two wire connector. With key on, there is approx. 12.1 volts. When I crank engine over, the other wire, the pulse wire, does not have a pulse. I checked it with a test-light, the test-light clip on the positive battery cable and the test-light tip on the other wire connector while cranking the engine. What is preventing pulse to the injectors? Is it the security lockout? ECM?