AC surging??

I have a 1999 Corvette and the AC is turning on and off at idle. I just replaced almost everythijng on the system. I took the car back in to get checked because I figured it was the low pressure switch and my buddy told me that he changed the orrifice tube, the pressure switch, and ensured the pressure on the low and high side are correct and it still does it? He said it has to be something with my computer??? With my tuner I can manually turn the AC on and off no problem but when in the "auto" mode under 800-1000 RPM it kicks on and off. Has anyone else had this problem?? Thank you!!