Banging the bottom of the tank can jar it and sometimes get you home. I have had more than one rig do this and get by once or twice. The last was a Jeep Cherokee? Got her home twice doing that.
The connector is usually not loose. GM argued that the terminals used were not sufficient and the lack of amperage was destroying the pump. I think they just wanted to use the same pump as the full size does and made us change connectors. Last few I have installed I changed to the bigger connectors and have had zero returns. Guess even if it is "voodoo science"...it works , so I will follow