Any update on this problem would be really good because mine is doing the exact same thing. Every now and then (perhaps 1 in 20 starts) when I go to start the car, the engine turns over but no ignition. Done it 3 times in the last fortnight; never a problem before this. Has always been in the morning with a cold engine. I can try 10 times in a row but no success. But if I leave it, go back in a few hours, then often it will start. Mine's a 159 2.4JTDm.
Initially I thought it might be the glow plugs; but all 5 failing at once? Seems unlikely; and besides when individual plugs have failed before I've had a dashboard message saying something like "Glow plugs not available". Also if it were the glow plugs I would expect that cold mornings would struggle more than warmer mornings. Seems no link to me.
I've also taken off and reattached the common rail diesel control wires just in case it's a connection issue, but again, no difference.
Is there any other sensor that would interrupt either the glow plugs or the injectors?
Any suggestions would be good. Sadly the appearance of this problem has just caused us to cancel our family half-term holiday for fear of getting stuck

. The car's booked into the garage but only for next week as this week was fully booked; too late to save our holiday.