1994 Nissan Pathfinder Fuel

I replaced 3 fuel injectors and had the other 3 cleaned. After putting the car back together, it started right up and I ran it around the block a few times. It ran great. I went to use the car about an hour later and it almost didn't start. When it did start it was only hitting on 2 or 3 cylinders.
I replace five of the six spark plugs (the almose new spark plugs were all foulded) and the engine started right up but started runnin rough right away. A lot of white smoke was coming from the exhause and I believe gas was dripping from the tail pipe.

any ideas on what should be done now. I am not a mechanic.