Common rail engine engines are a completely different kettle of fish, the first thing to do is have the codes read. You possibly have a faulty sensor or low fuel prerssure.

Back to the 1.8 Ford engine. My son has one in a P100 pick up which has always been difficult to start and whil a new battery and glow plugs improved it the problem is still there so I did a further investigation the other day.

What I found was that the alternator output was low at 13.6 volts and although charging the battery it was never completely full. The most telling thing I found was that there was only about 7.5 volts on the front glow plug which I suspected was due to a faulty relay, not so, it was due to high resistances in the wiring.

The lead from the battery to the relay was getting hot t the battery end so I crimped a new terminal on which cured that but I still had a lower voltage on the front plug, I checked and was getting a 1.5 v drop on the actual link leads so I made up one new one to go from the common terminal to the offending plug. The voltage is still not as high as I would like but it is starting much better now, an alternator or regulator change is the next move.