Nissan Patrol Starting Problems: Troubleshooting Guide

Hello!
I'm having a problem with a 1989 Nissan Patrol 2.8 D.
The vehicle won't start. It seems like it's not getting any diesel. When I try to start it and pump the manual fuel pump, it starts up somewhat.
My friend said that the car was running, and then suddenly it stopped. After a short time, it started again, but then it turned off again after about 30 seconds.

Can someone give me some tips?

Thank you in advance for your help!!!

Best regards, Daniel.

Could you please provide more information about the type of fuel injection pump? It sounds like it might be related to a diesel system. There could be a problem with the pre-injection pump, a leak in the fuel lines, or a faulty fuel filter.

It's a distributor injection pump (6-cylinder). The fuel filter has been replaced, but the problem persists. There is a manual pump located on the filter housing.
What is the best way to inspect the booster pump and the pipes?

Best regards,

Well, it depends on how it works. If it's an electric pump in the tank, check the fuse, listen for it, or try connecting it directly. If it's driven by the engine, check if diesel is reaching the pump.

Can you rule out air in the system?