I would check to see if you are getting spark at the suspected cylinder.
1) Take the spark plug out.
2) Put the spark plug wire back on the spark plug.
3) Hold the threads of the spark plug against the engine block to provide a proper ground for the spark plug (or use a clip-on ground wire if you want).
4) Turn off your shop light to darken the area.
5) Have someone turn on the ignition and start the car (or turn it over for a moment if it will not start).
6) As the engine is turning over, you will be able to see if that spark plug is producing spark. It should be a nice fat blue spark.
Obvious warnings: when the motor is turning over, hold the spark plug with an insulated tool or you might get the bejeezus shocked out of you. And make sure the person who is starting the car for you follows your instructions and doesn't hit the ignition before you are ready.
