Rick, can you turn off the suction line leading into the pump?

If so, try this.

Plan A

Turn off that suction line...completely

Put multiport valve in the filter position

Open the pump basket...there should be no water flow either direction.

Next, get a 5 gallon bucket and fill the pump basket 'til it overflows. I know some will go into the suction line...that's what I want.

Now, replace the basket lid and turn the pump on...keep the valve closed...you won't hurt the pump.

Most of the water should stay in the basket, since the pump can't suck it out because you've got the line closed.

Now, slowly open that suction line. It'll slosh around in the basket a good bit but, but hope fully, it will start to draw a larger and larger volume of water 'til it primes. It'll happen very quickly once it primes.

Plan B. If that fails to prime after a minute or so or you dont see an ever increasing flow of water into the pump, close the suction line again...pump running....it wont hurt it.

Next, Repeat Plan A above.....if it doesn't prime then, I am waaay off base.