Cadillac Repair: 1995 cadillac deville 4.9 engine, fuel pump relay, cadillac deville

Question
having problem with fuel getting into the carburetor changed fuel pump changed fuel filter getting fuel through the filter and lines but still wont start inless i use starter fluid then start run for a few seconds then cut off what is the problem u think a fault pump even if its brand new     Also had codes pop up in order p052 history 1039 history 1052 history pcm?  

Answer
Clear the codes from the computer FIRST.

Fuel pump test:

1. Get yourself a helper.

2. remove the gas cap.

3. have one person listen in the gas tank at the gas cap opening.

4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.

5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.

6. Does it ?.

7. If it does NOT run for the 2 seconds the fault is either the fuel pump or the fuel pump relay.

8. You need to put a fuel pump gage on the fuel line to be sure your getting sufficient pressure.