Hyundai Accent 98

Hello friends I have a problem with my car when I turn on the air loses too much and when you are going to start it seems as if you drowned yy when you have to climb Lomas only rises in the first march, but only with the air turned on but if it is off the car works normal
please someone who helps me with this problem

Check that the distribution strap does not have a tooth, that causes loss of strength and when you add the air compressor worsens the engine power