Search:

& when I said barbed fittings- they’re from when I plumbed the lift pump into it , from memory the standard Nissan steel fuel pipes just have a lip that rubber hose goes over then you put the hose...

I had a very similar problem - like old mate said put a piece of clear hose between the fuel filter housing / primer pump outlet & the injector pump - I nearly guarantee you’ll see little air bubbles...