Car starts then dies

I have a 1995 Buick Lesabre custom with 146.000 miles. About a month ago in the middle of running errands I went to start my car to go to my next stop and the car would start then die immediately. I tried it again and it started right up. Over the course of this month it will start sporatically but when it doesn't start it is taking more and more times to get it started. I took it to get checked out and after a week of trying to figure out what is going on they thought the security module came loose and they fixed it. The car ran great for 2 days and now it won't start at all. It will crank but it won't start and die like it did for a few weeks. The car runs pretty good once you get it started other than the car hesitating mostly when I take off from a stop. They checked the wires, the fuel pressure, battery and the ignition module and everything was fine. I just started a government job where I have to be at work by 4:00 am and I can't afford to lose this job. PLEASE HELP ME!