Next step - AC system not cooling.

[valfam]

Ok now I'm trying to fix the AC on my friends 99 996. Keep in mind the car was taken apart when he bough it, the car was in boxes so we are not sure what is missing or whats extra. I installed the old compressor, I did a vacuum test on it. It held the -25 psi vacuum with no problem I put oil and Freon but it did not cool the compressor would turn on I would see the clutch engaged but it never got cool. I check the high side and low side and the same pressure on both sides the compressor was not compressing. today he bought a new compressor and the same thing. same pressure on the low and high side. when I was putting in the engine and I was bolting things up I noticed a small white plastic things in one of the AC pipes above the engine that had a small hole in it, I'm guessing that's the orifice tube but I see a expansion valve in the front. which one should it be using it can't use both right? Any Idea what it could be. Should I try to take that white thing out of the line?