Car Acting Up Again

Well, it's been awhile, but my car started acting up again yesterday. It wouldn't start at the mall, but it eventually did. Last night, it wouldn't start at Menards, but it eventually did. So, this morning, I decided to get the fuel filter replaced (it needed it anyhow). That didn't help, and it wouldn't start after that. So, there's a new problem developing. Three years ago, I had to have the crank shaft position sensor replaced, and I wonder if this isn't the same problem. I'm sitting at Tuffy's now having it diagnosed. It could also be an ignition coil, who knows. But, I was also heading out today to do some storm chasing, and having a car that won't start is not a good thing if a supercell is bearing down on your position, or getting stuck in the middle of nowhere hundreds of miles from home.