Does your intake have a screen on it?? The Rangers I've had in the past do. If this is the case there maybe something that has become lodged in the tube. If there is a screen take it off and look in it. Maybe back flush it also. Just some thoughts.
"But if serving the Lord seems undesirable to you, then choose for yourselves this day whom you will serve, whether the gods your ancestors served beyond the Euphrates, or the gods of the Amorites, in whose land you are living. But as for me and my household, we will serve the Lord.” Joshua 25:15