DA6 or V5 compressor Da6/HR6 based a/c systems used a cycling system that causes the a/c to switch on and off as the pressure rises and falls, V5 based systems do not and much smoother in operation. Is there a switch on the accumulator up front? If so it is DA6/HR6 cycling system, if not then v5. With a cycling system you often (especially on a Fiero) feel the additional drag as the compressor engages. Is it 'jerky'? I don't think so but it depends on how you define jerky really. If it's just a feeling of additional resistance then that is normal.
Anything I might say is probably worth what you paid for it, so treat it accordingly!