Pontiac Repair: 99 firebird shuts off while driving, shaft position, speed bump

Question
i have a 99 firebird, my car started running funny (shutting off after going over a speed bump, or when i slow down to stop) i took it to a mechanic and they told me it was my fuel pump. so i replaced the fuel pump, fuel filter, air filter, car battery and got a oil change cost $1300.... it ran fine for 2 weeks and it started doing it again i took it back to the mechanic and he told me it was the spark plugs and wires and one of my cylenders wasnt working so i got those replaced cost me $500... it been a month and and its still shutting off but now its shutting off over speed bumps, going up hills, backing up, slowing down and turning corners... does anyone know what it wrong with it?

Answer
Hi Ashley:

What engine is in this car? It sounds to me like maybe a loose connection somewhere when the vibration from going over bumps is causing the stalling. If this car has a V6 engine I would look at the cranks shaft position sensor and the ignition module area. Maybe a loose power feed or a loose ground wire... It can be a lot of things But if the stalling issue can be induced and it's not an intermittant problem then it should be a bit easier to find the problem. Good luck :}