I working on my sister-in-laws 92 Firebird V6 auto. It has about 80,000 miles and has been garage kept its whole life. For the last 10, it hasnt been driven. A few years ago it was jumped, taken for a spin to the gas station, and on the way back home it started sputtering, it just made it home and hadn't run since. My father-in law thought it was the altenator, and he put a new one in at that time, as well as a battery. Didn't fix the problem, and he gave up. Now its at my house and i discovered no fuel pressure. I installed a new fuel pump(bosch) and fuel filter. I charged up the battery and began cranking it, nothing. I confirmed fuel and spark. Finally, it started and ran for a bout 30-60 seconds, before it died out. It just cut out. After that it would not start again. It would want to start, kick over here and there, but not catch. I charged it up again and tried again the next day, after some cranking, it started again, i drove it around the block, it seems to run great, smelled a little eggy, but it had been a long time since it ran, seemed kinda normal. Once it was sitting in the driveway, it cut out, it did seem to start back up a time or two fairly easily, but after a while, no more. Now i know the gas is kinda old, but it didnt smell to far gone(not like turpentine) and it seemed to run great and then just cut out. Does this system need to have a certain voltage to run? Because it cranks strong. Possible an engine computer? Your thoughts?

 

check fuel presure, if that checks out also check for spark once it dies and wont restart

check engine light on?