Hi Perrka, since many years modern diesel engines (as also Nissan Navaras) use the common rail technology. This means that there is no need for any "fuel pump timing" because the fuel pump is degraded for only producing enough fuel pressure in the common rail and not worrying when to let it into the cylinder/combustion chamber. This job was trusted to the injectors, sensors and the ECU. That said the (wrong) timing issue can only happen in two ways: 1. Mechanically-the two timing chains are/were not installed correctly, 2. Electronically-the two sensors for the cam- and crankshaft position are malfunctioning. If your problem was to be number 1, you wouldn't be able to drive your car without destroying the engine in a second. If it is number 2, the diagnosis is simple - when the car is running, disconnect one of the two sensors and when the engine does not stop, you found the problem (DISCLAIMER-Do so at your own risk!). It would also be beneficiary to know when the timing chains have been replaced, how many km do they have on them? It could also be the case, that they are stretched but the sensors are ok. The injectors could also be a part of the problem you are facing. When was the last time that they were checked? They should be every 50k km.