check the basics-sounds like too much fuel or not enough spark.

too much fuel-leaking injector and/or fuel dist. MAYBE co is too high or the eha isn't getting correct orders. o2 sensor could be way off.

not enough spark-tired plugs ,wires, cap, rotor and or coil. look for any discoloration at the coil bracket. any white you see is spark escaping, looking for the path of least resistance.