Gosh - all sorts of different opinions on this one... I'm assuming its an EFI not carby, if so then:- There is a valve which the ECU controls to temporarily make the regulator force a higher fuel rail pressure to collapse the vapour that can build up during heat soak. if this valve is blocked (as one port is open to air) or not connected or stuck closed then you will get exactly the condition you describe but, its far more likely to occur in summer. Fact it happens in winter is a bit strange. Although if your fuel pressure regulator has developed a heat soak fault and is letting too much pressure bypass and your solenoid isnt working then both those problems together could well explain the condition. One way to see if it might be the case is to force the pump to keep going for a longer while before you actually crank it. Such as, turn on ignition, wait for pump to stop, turn off and wait 20secs, then repeat, do this a few times. This is only as a diagnostic suggestion and not something you need to do each time etc ie. If it helps then it does point to a vapour lock issue, then you can look at reg and solenoid etc, There are other possibles, but check the above first. Not sure where those things are on the VN though, Cheers

does anyone know where the above valve is

suggest find pressure regulator and follow where the sense port goes...