Just because you have stuff flying out, which could very well be gas, it doesn't mean that the gas is getting in there at the correct time. How did you come to the conclusion that it is cylinder #3? Did you start pulling plug wires with the engine running to determin this?
If you are certain that their is a spark at the end of the plug wire, then all that is left is fuel. I would swap out injectors (if you have spares) or take all 4 down to an injector rebuilder and get then flow tested and cleaned (if you are going to do one, then PLEASE do all four). The injector could be leaking and flooding out the cylinder, or a extremely rich condition.
You might be able to check for Gasoline contamination in your crank case oil by smelling the dip stick or the oil cap.