'94 buick lasabre starts then stop immediately

so i have this problem guys. i'm not a machanic but i need to know what is wrong with my car. i own a '94 buick lasabre that wont start. It cranks, the engine starts but then it immediately dies out.:banghead: It acts like its going to turn over with no problems but then dies out right before it turns over. I got a book for buick troobleshooting and they said it could either be a clogged fuel filter or the feul pump dooen't create enough pressure to sustain the engine. i'm not sure which one but it might help to know that this didn't start happening until i let the car run out of gas a few times (money was tight). This reaccuring problem can be avoided if i keep over 1/4 tank of gas in the tank...it will start with no hesitation; but as soon as i let the gas go below 1/4 tank and turn it off, when i try to start it again it fights with me. there is no ryme to the reson...if i just keep trying to crank it for 5, 10, sometimes 15+ min. it will start eventually. and then the cycle continues. i've had 4 mechanics look at this so far. PLEASE HELP!

Have any of the mechanics checked fuel pressure @ prime & idle?

had the same problem last year and got alot of info on this site,but there were a couple of things that could cause this problem.first off it's probably the injectors not firing after the initial start. the anti- theft system is usually the culprit but after following the posts to check the system it ended up being the PCM. read on and good luck.