Hello
I have a '94 Tercel as my second, city car. The A/C has been running barely cool at the max setting, taking 15 minutes maybe to even get to sorta cool. Last time I had the A/C looked at was back in 2001, when I had it converted over to R134 refrigerant and fully charged with it. So I bought a bottle of the stuff, one with a built-in pressure gauge. The first reading I got was just above 20 pounds--about 5lb out of spec I think. Then, without me adding more refrigerant, the pressure started to rise, up to about 32-33lbs. So I get back in, and the air is mucho colder.
So, what exactly could I have done to fix it? The R134 bottle I got has a button you have to press down (rather firmly) to release anything, and I didn't press it at all. Could just checking the pressure have stirred up some refrigerant that had "settled" or something...though I guess that doesn't make sense since gas doesn't really settle.
As you might guess I know relatively little about auto aire conditioners; doing something like this is about my limit as far as repairs on 'em can go.