Miata - Airconditioning - Shifters :: 1994 - A/C Running Hot?

For the past maybe 10 months, my car has been giving me new AC problems. The AC runs just fine when I'm driving normally or on the highway (basically without stopping for long periods of time and out of traffic). But when I stop for a long time (traffic, drive-thru, long light), my AC begins to run hot. To be more specific, the car actually begins to feel like it is running with more difficulty, as the engine starts running loudly and then I know that it is game over and it begins spitting out hot air. I generally just turn the AC off and put the windows down until I can get moving again, and then the AC is colder when I turn it back on.

Now, about 5-6 months ago I took it to my Mazda guy and he checked it out. Of course, it did not do what I wanted exactly, showing him what really happens when it sits for too long. Anyways, he said that everything seemed to be fine & both fans were working, but that the freon (r134) was low and he charged up the system and added some freon. After this, the AC was running MUCH cooler than it was before and the problem stopped.

That brings me to the last couple months; the problem has returned. This indicates to me, perhaps, that the freon has leaked out at this point, so it needs some more r134, but with dye, so that they can get a sniffer and pick the leak. Additionally, the engine is not overheating or anything of that sort, so I don't think it has to do with the radiator or coolant. I have essentially replaced almost every other part of the AC system in the car within the last 3 years. I have replaced the condenser, one of the fans, the water pump, hoses, everything you could imagine that isn't the compressor or the second fan.