I'm having problems with my 2003 Sierra with the 4.3L. It turns over and the the fuel pump works. I've checked the ignition system and it is firing. This started while I was looking for a short due to the battery would run down at times when left parked overnight. I had pulled all the fuses in the box under the hood and the side panel inside the door and re-installed. After doing this now it will only turn over but not start. Any ideas?
