[5cilinder]

Besides an engine light there can be more faultcodes wich can be made visible with vida or the torque app
Do that first..... if you have fuelpressure codes check connectors (they are crappy) on the railpressure regulator and measure resistance on the sensor itself(i dont know where the relay of the prime pump is on this model
the primepump can be heard buzzing with contact on preferably with not much fuel in the tank or put a pressuremeter in de feed line to check if it builds up pressure (even if its activated and buzzing it can go broke).
Check the fuel filter on blockage
If thats all ok do a leakback test on the injectors and a fuelcorrections readout on the injectors.
Other codes could be if circuits are open for the electrical wires of the injectors.
Reading out fuelpressure while cranking the engine is also informative with torque or vida
The idle fuelpressure for this engine i dont know but it has to be 350 bar or higher

The "cold"in this time of year is no issue for starting because at these temperatures the glowplugs arent activated (if you live at great heights it could be needed at these temperatures) and to be checked but i asume its not
(you live in australia if its above 5 degrees celcius it should be ok or if its borderline if you crank long enough there will be more compression heat buildup and the engine will start if the plugs are the culprit)