misfire

check your wires for cracking or deterioration. (Quick test best seen in dark, with engine running take a squirt bottle fill with water and set on mist setting, spray around wires and distributor but do not soak, if you see a spark show then they are bad wires)

check spark plugs if the gap is too large or they are badly corroded then it will not fire properly.

if there was no tune up done lately then you should change you plugs wires cap and rotor anyways.

just wanted 2 give u somewhere 2 start