I have a 1993 4Runner with a 3.4L out of a 96 Tacoma. The A/C blows nice and cold when driving down the road, but as soon as I get to a stop light it starts blowing warm air. I then did a little bit of research and it lead to me the throttle body or IAC being gummed up. I cleaned the throttle body the best I could and now I noticed that the A/C compressor doesn't turn on when I push the A/C button in the cab. So I made sure the button was pushed in and then I hit the gas a little bit and went and checked to see if the compressor turned on. Sure enough hitting the gas a little bit made it engage and it continued to stay on at idle. I left it run for about 5 minutes and it stayed on. I've been doing some reading and it's leading me to believe it could be the A/C amplifier. Does anyone have any insight/suggestions?

 

Off the cuff - before you go crazy guessing, hook up some gauges to the AC

It may just be low on R12 / R134a

BTW - which compressor are you running (the 3.4L or the 3.0L or the 22RE)

 

Already checked refrigerant level and I'm good, running the 3.0 compressor

 

The ac amplifier can shut the compressor off if the rpm is not high enough. And the ac idle up relay needs to be working to maintain higher rpm while idling with ac on.
just some ideas
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Thanks guys, will look into this stuff this weekend and see what's going on.