stumped

i have a 94 bonneville the reves up then cuts off the power windows won't work i've taken the car to two different shops one said a security code came up the other said it was the fuel pump, had the fuel pump replace, the battery, alt car still won't start when ether is sprayed on the throttle body the car starts but doesn't stay started, could this be the neutral saftey switch, or the fuel pump relay or is the computer bad

Welcome to AF, check under the l/s front sill plate/carpet area for a bad ground junction in the harness, this will kill the fuel pump and power windows.