A couple of questions:

1. What do you mean by "it bubbles"? Do you see air bubbles in the pump basket while it is running?

2. DOes the pump lose prime immediately after turning on, or does it take some time?

3. If it does run for any time, do you have normal pressure, or is it higher or lower?

4. Did you say it takes several minutes for the pump basket to fill with water (with the pump off and the lid removed)?