1999 BMW 318i smoking

1999 BMW 318i mileage: 60,000. I changed the water pump and fan clutch. Now the engine runs poorly. I removed the intake duct from the intake manifold and the engine smoothes out and stops smoking. I have replaced the airflow sensor and the temperature sensor. The engine still runs rough and smokes. The smoke smells like gas, like it is burning rich. I have checked the timing and replaced the rotor and distributor cap. I have also replaced the spark plug wires.