Can anyone tell me if the allroad 2.7t fuel pump primes and for how long when the ignition is switced on.

I replaced a faulty fuel pump on my Allroad and now the car starts and drives perfectly except for one thing.

When I leave the car parked overnight or for several hours, the engine cranks over for about 5 sec before it will start.

When I turn the key to the on position sometimes I hear the pump prime for about 2 sec and other times nothing but the car still starts fine, except after several hours between starts as mentioned.

Thanks