Question
Last summer we installed a 1.5 sprinkling pump and sank a point. Because it was outdoors we drained the pump and disconnected the plastic suction line at the check valve. We open the checkvalve to drain the line. This year when we hooked it back up it will not pump full flow. The pump was under warrantee so it was replaced but he problem is still the same. I hook a water hose up to the fill hole of the pump to keep it filled with water while drawing prime the first time. If I have the hose and water from the spigot supplying water to the pump it pumps fine.. but that fill hole is on the discharge side of the pump. As soon as I turn the spigot off the flow drops by at least 2/3. Any suggestions for this 1 year old system??

Answer
A couple of things come to mind.  First, the well line may be plugged or have some other obstruction.  Second, if there is a foot valve at the bottom of the well line, it may not be working properly.  You would probably have to pull the well line out of the ground to inspect it.