Replaced starter and now the fuel pump won’t come on and will not start

It cuts out when accelerating, especially around the time that it "changes gears" around 30-45 mph..it doesnt do it when you accelerate quickly (drive it hard) but when you accelerate slowly is when it does it. It will cut out for a few seconds then gain power/momentum again. We changed spark plugs and ignition coils, still doing it although not as bad as it had been. Could it be something related to throttle body or fuel pump/filter? Ive owned nissans all my life and the parts for this car are so much more expensive so really looking for some help please! Thanks!