i have a 94 buick lasbre custom and it starts but instanly dies and sometimes i can...

[B S]

...get it running for a? i have a 94 buick lasbre custom and it starts but instanly dies and sometimes i can get it running for a couple of min sumtimes then it runs really rough and dies when you give it gas it has good spark on all plug wires and its getting gas im thinking it might be a sensor or something like that maybe or the computer is going bad im not sure what it is tho so if you can help me out with some possiblilitys on what its is and the price