Hey yall,

My 2000 Z28, basically stock, has been having a/c issues lately. After driving for about 30-45 minutes, the a/c will cut down to about 20% power. It still blows cold, but just loses power. If I turn it off for about 10 minutes, it will be fine for another 45 min or so, then cut down again. Also, when I accelerate, even if the a/c is working properly, the a/c will drop in power and come right back up when I let off the gas. I had a mechanic tell me to clean or replace the IAC valve, because is most likely the problem. Any thought??

Thanks

 

He's an Idiot. The IAC stands for Idle Air Control which bypasses air arond the throttle plate to increase idle speed when you increase engine load like turning on the AC. The air conditioner in your car is a variable displacement compressor which uses the low side pressure to determine the cooling load the control valve is mounted on the rear of your compressor. Handy right. The control valve has two functions, sense the low side pressure and cgange the compressor stroke to match load. Soput some guages on your car and check the high and low side pressure before you do anything else. Look at how the values change when the system stops cooling.