I recently had my fuel pump replaced after it failed. Since day 1 after it was replaced the car will not start on the first try after sitting for long periods of time, i.e overnight. The fuel filter was also replaced at the same time. During startup I hear the pump prime. My mechanic claims it's most likely due to a faulty valve in the pump that is causing this. Once the car turns over there are no issues. If the car sits for only a couple hours it has no problem starting on the first try. Any suggestions before changing the pump again?