I have had the most bizarre time with attempting to fix my A/C on my 93' LT1. I've just about replaced every single part on the entire system. I have new hoses, expansion valve, dryer, compressor, high and low pressure switches, plugs. The only two things I have no replaced are the Evaporator and Condenser and I blew air through both of those areas on the system to make sure they werent clogged.

According to the guage, I am having high pressure problems. I would get the low pressure guage between 21-29 PSI and at idle everything would seem fine...but then i would get the RPMs up on the motor and the compressor would start kicking on and off...and sure enough...the low pressure gauge read that the pressure was to high. So i would let a little freon out, and I did that until basically no freon was left in the system. I dont understand what can be wrong. I'm going to go take off all the hoses right now and blow air through them while they are off the car, just to re-assure myself that there are no kinks or clogs.

Cory

 

Did you pull a vacuum on the system before recharging?

 

yep, always for atleast an hour...and i would always get a good vacuum. I believe I may be on to something now however. It seems as tho, the system may have been loaded with way to much PAG oil. Lets put it this way...the system is said to hold only 8 ounces, and im positive that I have removed atleast twice that amount alone from the system by remove the hoses/expansion/dryer etc...and blowing air through them.

Cory

 

What is your high side pressure before and after this happens?