I own a 91 Camaro RS V-6 3.1 liter. My A/C compressor is pretty messed up. Whenever I turn my a/c on, the compressor kicks in and I can immediately feel a draw in performance. It runs really rough, the engine tone changes from 1 solid, healthy tone, to 2 or 3 shaky, vibrating tones overlapping. It also shakes the hell out of the car. The compressor won't stay on though... Usually when I first turn the system on, the compressor runs for a few seconds and then shuts off. It'll come on in a few minutes, for a minute or less, and then shut down again. It does this constantly for random points of time. Also, when the compressor does shut off, my RPM's jump by 100-250, depending... And when the a/c is on but the compressor shuts off, I'm hearing an odd noise. You know the turn signal noise, the little clicking noise? Well, I get that noise when the compressor is off...it's slightly louder than my barely audible turn-signal click, and it's deeper. Is this some sort of electrical thing? Or is my car trying to tell me something? Thanks all.

PS-I'm not sure if I'm low on freon, but I bought the car several months ago, when I was told the freon was fully filled.

 

Drop in performance, change in idle quality, etc. is all perfectly normal. A small engine like that really has to struggle to move the car around in the first place; and the A/C uses a significant amount of power, leaving that much less available for its main function.

It cuts on and off because it's low of Freon. There's a low pressure cutoff switch, in the low pressure side of the system; when the pressure there gets too low, it shuts off to prevent damage to the compressor.

------------------
"So many Mustangs, so little time..."
ICON Motorsports