Well, I have the same problem with my towed car, it was real bad a while ago but I got it repaired so it's now back to normal
And what you describe is NORMAL
Story: While I had my RV back at the factory for some warranty work I had a nice chat with the AC technician there, Now understand since we were talking about my 1992 Lumina APV and not the 2005 RV there was no reason for him to tell me anything untrue.
Understand further I confirmed what he told me with some service manuals
A/C draws a lot of power, in the old days (Back when we had big engines and breaker point iginations) there was power to spare so we more or less forgot it, but with today's newer, smaller, more fuel efficent engines there is not as much spare power, to the AC is actually run not by the dash switch, but by the car's computer system.
And when you call for heavy duty acceleration, in order to get the most power to the wheels, it cuts off the AC. This is for cars, Motor homes the AC is a much smaller (percentage wise) portion of the load on the engine, however since the technology is there, they use the same type of computer and programming/ So what you describe is Working As Designed.
Your 1993 likely also uses vaccume to decide when full accelaration is called for.
I had other clues (Poor cruise control operatoin) that there may be a vaccume problem and sure enough there was, Bad servo on the Cruise (Valves leaking) Dealer replaced and though the AC still cuts out if I floor it,,, It hangs in there if I'm gentle on the pedal
You might wish to check all vaccume hoses and devices.. Since it's a teenager, it's time to do that anyway
Now... one thing that can make a difference. As I said, my car it got real bad. We investigated and found a vaccume leak (On my car the computer decides I want full acceleration by measuring vaccume, My motor home is a bit different in that regard)
