Pontiac Repair: Pontiac falling DEAD....., crank shaft position sensor, pontiac bonneville

Question
1997 Pontiac Bonneville SSE,3800 V6,140K. New plugs,wires,oil,fuel filter and 2 new coil packs. My last 3 fill ups after driving maybe an hour she starts to sputter and idle up and down ultimately falling dead. I'm thinking my fuel pump is going out b/c each time I've poured B12 inside gas tank and within 45-60 minutes she starts and runs fine. My question is,the problem a matter of replacing the fuel pump and assembly or replacing the final coil pack. Or doing both as all above repairs were done the day before I bought the car around the first week in March. Any suggestions?

Answer
Hi Chris:
so when this dies it will not restart untill it cools down? If so it can be either fule or spark related. when it does die you can press on the fule pressure valve on the fule rail and see if there is fule pressure there If not good chance it's a pump going bad. If it has pressure then I would still lean that way it may have pressure but not enough or not enough volume. A fule pressure gauge is the onluy real way to tell for sure. The other thing is a spark tester when it dies out put a tester in one wire at a time and see if it has spark  see if it dioesn't have spark on all 6 wires or just a pair of wires if it's just a pair it could be a coil or a module. if you loose it on all 6 chances are it needs a crank shaft position sensor Pretty common on thatengine. good luck :-)