I pulled a valve out of one of the compressors I had on the shelf, recovered the refrigerant, swapped the valve out real quick, pulled a vacuum for 30 minutes, charged it back up and it would not build pressure at all with this valve. So, I recovered it again, swapped it out with another one I had etc, initially it did not seem to be working either, but then it "kicked in" and pressures started looking like they should and it started producing ice cubes. I let it run for about 20-30 minutes and it never seemed to cut out. The true test will be next week when I drive the car again. If it still has the pressure drop and lack of cooling I will order a new one. I would have normally just ordered a new one but I just wanted to give it a shot and see if I could cure it with what I had on hand.