Just had fun with my 06 Doblo 1.3 Multijet. It let me down twice, would not start when Hot. The RAC man said it was the starter motor. So got a new started motor fitted £190 and the first time l use it the same thing happened again. Then it would not start from cold, so looked on this forum and found a bit on MAP's.
Took out the old MAP (its very easy) and noticed lots of black gunk on the sensor. Pop in a new one £13 and it started first time and now runs perfect.

After leaving the car two days, would not start again, it took 6 to 7 goes but after that ran perfect the rest of the day. Now going to fit a new Camshaft Position Sensor, and hope this solves the problem.

No still having problems starting, its still saying Glow plug problem, but l known the plugs are new'ish. Not sure what to do next.

Put some new quality glow plugs in, and it now starts first time. SO DON'T BUY CHEAP GLOW PLUGS. All was going well then the the engine fail light came on. So took out the sealed MAF sensor and spray it with Mass Sensor Cleaner, and crossed fingers all seems well, no warring bleeps or glow plug warning lights, so far.