Cadillac Repair: 2000 Escalade, spark plug wires, turning the key

Question
My 2000 Escalade randomly won't start. It has happened a couple of times in the last week.  It seems to only happen in the mornings when it is cold out, since it will always start just fine when I get home in the afternoon. In the morning after turning the key on, the fuel pump kicks on and the engine turns over but will not start. We have replaced the fuel filter and the fuel pump. Any help would be great.

Answer
When you know that the engine is not going to start. Remove one of the spark plug wires and hold it about 1/4 inch away from any metal surface and have someone try and start the engine and see if you can physically see a spark coming out of the wire that you are holding 1/4 inch away from any metal surface.