Nissan Quest '97 vibration after cold engine start

Nissan Quest '97, 102000 miles, v6 engine.

The Engine virbrate for 1 to 2 seconds before calming down to normal idle right after cold engine start. It won't vibrate when engine is hot. I have recently changed water pump, thermol stat, timing belt, driving belts and erg valve and hose.

Nissan dealer told me that my fuel dump makes noise and needs to be replaced. I am not sure if that contributes to the virbraion.

Also at 102000 miles do you think it is good time to replace plugs, plug wires and cap?

Thanks in advance