1990 Mazda Miata, I bought Used A/C Compressor, When A/C is on when i start the car it struggles to start?

I have 1990 mazda miata, bought a used A/C Compressor and bought the oil since it was used. Supplier said compressor was in great shape (prob not). Well when A/C compressor or A/C is on when i start my car is struggles to start? when A/C compressor is off car will start fine. A/C compressor even makes a wierd noise nothing load but not normal. Runs fine and noise stops when gas is pressed? Could it be the A/C Clutch???