Not an expert but I'm pretty sure all Crossfires have an external fuel pump. I know my 06 does because I just changed the fuel filter/pressure regulator yesterday and the pump is right next to the filter. Very easy to get to once the car is off the ground. You mentioned you added fuel and it still would not crank over. Does that mean the starter didn't crank the engine or it just wouldn't start with the starter engaging? If it does not crank over you have a starter problem, should be easy to troubleshoot. If it's a cranks but no start condition who knows. You could put a gauge on the fuel rail shrader valve with key on and expect to see ~55 psi on the gauge. If it's not there you have narrowed it down to a clogged filter or faulty pump. Problem may be in the relay control module, cold solder joints or burnt contacts. Good luck with it.