Maybe there is still an issue with air in the fuel filter housing and as long as the primer is firm to push in then its okay if the resistance drops quickly and you find you have to pump it more to fill the filter then replace the primer and also the filter if it hasn't been done for a while. Start there and see how you get on
Black with yellow lead is an earth but where to no idea, unless its back to the battery negative directly.
On that note, check all earth leads are in tact and corrosion free as quite common fault on Nissans