96 Maxima cold start fuel system VIBRATION

[Rproto62]

I have a 96 maxima that when started for the first time in the morning has a vibration transfering up through the floor. I have traced it to the fuel system because the only time you can hear it is while sitting in the car. Open the hood and it disappears. Put your hand on the fuel filter and you can feel it as well as when you touch any part of the fuel lines running under the car. This problem disappears after the car is driven for roughly 3 or 4 miles. Is there a cold start fuel injection motor that could be causing this problem because it is gradually getting worse. Thanks for any input.

[maxhopper]

Welcome to NICO!

The only motor is the actual fuel pump itself.

[Rproto62]

I don't think it is the fuel pump for the reason it only appears when the car is cold. It isn't rpm sensitive which I would think rules out the engine. I'm looking at the cold start side of the fuel system. The fuel filters have been changed.