I'd chek the inginition system, but also the air supply, if there isn't enough air the plugs always have fuel on them,
BTW I had a similar problem with a 94 sentra, it was very difficult to start and when you took off one plug it has a lot of gas on it, we checked a lot of thing and it resulted to be the rotor of the distributor (i.e. ignition system)
hope this helps
