What are the symptoms of an overcharged AC unit. I turn on the AC and the RPM drops to almost 0 and the engine acts like its running on 2 cylinders you turn the ac off and its fine. I just charged with 134 and the psi was 42 could the compressor be overcharged and dragging the engine down and causeing this??? I dont seem to smell any burning smell and the clutch is not red hot so WTF??