I have an 05 escalade esv,6.0 . I have fuel pressure at the rail. It starts with starter fluid, but dies. If I press the gas pedal it dies immediately.

Does it fire and then die, or does it just crank with no fire at all?

If it'* starting with starter fluid, then it sounds like you have spark, and you have pressure at the rail. That leaves the fuel injectors. Check the fuel injectors fuse. Also, do you have a security light on your dash? What is it doing? Could be a VATs issue. Try a different key. This at least gives you a place to start. I'll poke threw my service manual and see what I can find.

OK, I see you have a immobilizer, have you changed or added keys?

I'll check my injector fuse. security light is not flashing,but i'll try another key.

It sounds like its a fuel pump problem, if you can start it with starter fluid then dies it seems like your not getting enough fuel PSI.

You can also use a NOID tester. A place like autozone will know what that is. It will test your injectors to see if they are pulsing, it'* easy to use. If no pulse, then check fuse, if that'* good it could be a bad crank position sensor.

That is a good point, the OP stated he had pressure at the rail. Guess we should ask how much pressure. 10psi wont cut it. 48-50 is what I believe it should be.

I changed the fuel pump, still no help.

55 psi at the rail.

My emission light comes on periodically, but seems to reset.