Yes we can continue this conversation after rating Jamie,
If you Do have voltage to the inertia swtich when cranking, then the PCM relay is good, because it powers up the Fuel Pump Relay. It could be the Check engine Light is burned out, or , the PCM itself is defective.
Another way to check the PCM relay is, With KEY ON , you should have power at the fuel injector
RED wire, constantly with KEY ON. If you do NOT have power at the RED wire at the injectors with KEY ON, Then I suspect an open circuit from the PCM relay to the injector harness.
Get a fuel pressure gauge on the fuel rail, if you have power at the inertia swtich, then you should have 35-40 psi fuel pressure at the rail, I would double check that. No fuel pressure to the injectors, no start of course.
If you have fuel pressure, Then I would check for spark when cranking at a plug wire, if you have spark, then you need a noid light or 12 volt test light, and check for injector pulse. Unplug the injector harness, and wire a 12 volt test light, or a noid light inbetween the 2 pins in the fuel injector connector. If the light blinks when cranking, you have injector pulse, If it doesn't blink when cranking, and you have spark, Then I would replace the PCM.