AC/Rear Window heating kills car

[ickna11]

I can't use my AC or turn on the rear window defog without it killing the car. I can run the AC for a little bit but it causes the engine to rev up and down lower and lower until it kills the engine. Rear window defog does the same thing. I have a swapped h23a with a chipped p28. Could that cause the engine not to rev up properly to compensate for the fans turning on? It's been like this for a long time and I can't remember when it first started.

 

[Enne]

I know the AC compressor demands a few HP from the engine to run. Perhaps something with the programming or your chip isn't giving the right values to keep the engine stable when the compressor kicks on? I'm not sure.