Nissan Repair: air conditioning problem, full size chevy, chevy van

Question
I have a 1995 full size chevy van. I just purchased it and the air conditoner was not cooling very well. It has been changed over to 134a refridgerant. I added a little of the 134a and the compressor started smoking. It was cutting in and out before this happened. Do I have to much refridgerant or has the compressor decided to take a dive?

Answer
Hi Greg -

The compressor was short cycling (cutting in and out) before. Have you connected a pressure manifold to the system to check first? Not advisable to arbitrarily pump freon in, as short cycling could be caused by several things. The system has pressure sensors that shut the comnpressor off if head pressure gets too high. When was the last time you had the system flushed and filter screen replaced? There could be blockage in the system.

With the A/C running, shoot some water on the condenser. Does the compressor stop short cycling, or air get cooler? if so, you probably have some system interference.

Hope this helps -
aloha
calvin