94 LeSabre odd starting problem

My 94 LeSabre with 290,000 miles recently started to have a starting problem. Sometimes, the car will start and then almost immediately die, and giving it gas does nothing. The other day it probably did this 15 times before it started and I am not sure if I did anything different on the 15th try or not. When it does start then it runs rough. Other times it starts fine and runs good. Anyone have any suggestions what might be the cause of this? I have not yet taken it to my friendly mechanic for getting the codes read, thought I might try it myself with the help of this forum first. Thanks

When it won't start do you have spark, fuel pressure, injector pulse?

I don't Know. I just assumed that since it actually started and then died that I would have had both spark and gas, especially since it eventually started. Maybe I better wait until I have someone look at it before I do anything. Thanks