2003 Audi A4 Fuel Pump issues

I bought the car used with a timing belt problem. I fixed that and a host of other issues. The car started but was running really rough. The engine light came on with the Low Intake Temperature sensor, which I replaced. Still the car ran rough. I checked the injectors and found one damaged and replaced them all. Since I fixed the injectors, the car has not started. I figured it was the fuel pump since I could not hear it priming when I turned on the key. I replaced the fuel pump relay and that still did not help. I then replaced the fuel pump with a new one, and I heard the pump prime once or twice and then it went dead thereafter. I still have not started the car yet. What could possible be wrong that is cause the fuel pump problem? Any help will be highly appreciated. Thanks