Feul Pump on 1999 Pontiac Bonneville

After we replaced the fuel pump on the 99 bonneville. the car only starts when it wants to. What could be the casue of this problem.

Is it cranking with no start? Have you checked your base fuel pressure?
Yes, and What is the base feul pressure and how do you check it?
An experienced technician with a good manual gauge will be able to check the fuel pressure. Figure low 40's in PSI.
is there a way we can get to the fuel tank thru the trunk of the car?
No, unfortunately, the fuel tank must be lowered from the vehicle.
1 more answer
the fuel pump is not sitting in the tank correctly or try changing the fuel filter under the rear driver door underneath the car near the frame