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on an 1986 there should be a mechanical plunger that holds the throttle higher when the AC is on, ac kickup
or a more efficient compressor / ac system, or if its really a bother, go to a variable displacement compressor, they dont cycle like clutch on-off ones do, so the horsepower draw is more smooth. it will still draw on a high load for the ac, but it wont be the way the OP complained
meaning the idle probably could be ticked up a tiny bit overall and then not notice
