Technical Rough running when cold

[DJNumpty]

Hi a newbie scratching his head after pulling his hair out.
I have a 2009 Doblo 1.9 multijet diesel and has issues idling and running rough when cold. Start up fine if left idling every now and then it has like a misfire, if I try and drive it from cold it coughs and jerks between 1200 and 2000rpm almost like a flat spot on acceleration but as it gets up to running temp it get easier until you end up with a tiny flat spot about 1800rpm but perfectly driverable.

His a list of tried thing
New cambelt , water pump and pulleys etc
New engine mounts
New glow plugs
New maf meter
Thermostat
EGR valve
Regen
No fault codes on multi scan

Anybody got any ideas ?

 

[cris1117]

Hi, I had exactly the same thing on a Peugeot hdi I went to a diesel specialist he fitted a new fuel filter and advised to use some JLM Diesel extreme clean (not cheap).
I had my doubts about additives but must admit it worked a treat.