turbo diesel missing and surging

i was wondering if someone here can help me. We bought a 2003 3.0 turbo diesel patrol on the weekend and hubby drove it from perth to Kununurra. He left perth all well and good, and after making his first fuel stop, the car started missing and surging. Hubby lost power and couldnt get more than 60kms/hr. After fuelling up and putting some fuel injector in at port hedland, it was running fine until refuelling at fiztroy crossing, where it started doing it again.
Has anyone had an issue like this before and know what it could be?
My brother in law is going to change the fuel filter on the weekend but is there anything else we should be looking for?

Hello your welcome,,,please.maybe thank you..

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Sounds like a dodgy fuel filter to me.

Thank you, that's what we were thinking but having not owned a patrol before I thought I'd ask.

Maybe even water in the fuel?