Alright, I'm going to admit up front that I don't know all that much about engines, so pardon me if some of what I say might not make sense, it's what I've been told(or at least, how I've interpreted what I've been told).

1991 Firebird, 305TBI

For about 2 months now, my 'bird has been giving me starting problems. When I turn the key, the engine cranks over... and cranks, and cranks, and cranks, but never catches. If I disconnected the battery, and came back 5 minutes later and reconnected it, It would start. At no point was the service engine soon light on.
When I first took it in to get it looked at, the mechanic I took it to thought it might be the fuel pump, so he replaced the fuel pump and fuel filter.
A couple days later, it was doing the same thing again. I took it back, and this time he did a full tuneup, which appeared to fix it... once again, for a couple days.
I took it back again, and this time he replaced the distributor module, which had apparently gone bad. He also replaced the battery, claiming that a loose post on the battery had caused power surges to go through the electrical systems, and that that was what had fried the distributor.
A couple days later, it was doing it again. This time, I took it to a different mechanic, who after looking it over said he thought a tuneup would fix it. So I once again got new plugs, wires, etc, etc. This guy also said the although the distributor module looked new, the distributor cap was cracked, and replaced that.
A couple days later, It was once again doing it. I called the guy back up, and he took it in, hooked the car up to the computer and pulled the codes(which I neglected to get) even though the service engine soon light wasn't on. He then claims that the reason that the car won't start is that 3 of the "drivers" in the computer are bad. After pricing the drivers seperately, and the entire computer, he called me back and told me he'd gone ahead and replaced the computer because it was the cheaper option. OK, fine, and it starts now? Sure! Oh, and the check engine light is on now, but it's only the O2 sensors, nothing to worry about.
A couple days later(now) it is once again not starting. and I'm tired of paying out the nose to get the same things done again and again, and it not working so consistently. I just want my poor car to feel better, so she doesn't have to complain and stop working on me anymore...

So, if anyone has any ideas, could they please post? At this point, I'm willing to try a fair amount.

 

Your profile says you have a fuel injected car, so It could be a faulty fuel injector(s). Your starter might be bad also, not giving your engine enough juice to turn over. It seems like these mechanics are giving you the run around. If I were you I'd go out and buy the chilton and haynes maintance books for the 82-92 firebird (they go for $10 a piece). It has a whole section that takes you step by step to find out the problem. This way if you not good with your hands, you can at least tell the mechanic whats wrong.