Firebird problems, help..? Options

[monkeywrench]

By bf recently got a firebird and hes almost done fixing it, except for what happenend the other day. He took it down the road for a test drive, and at first it drove perfectly and then died. and would not start. he has changed out coil packs, and tried switching out the coil pairs and that didn't work. He said the engine will try to start, and he checked to see if the spark plugs were firing, which they are. Do you guys have an idea of what it could be thats going wrong?

Any help would be appreciated.