need some help on this. ! 46K 150 bhp CDTI. this car has had a lot parts replaced to try and slove a fault by the dealers. The problem is after the car has been resting for over 2 hours it starts up ruff and above ave. smoke comes out the back. I can stop this by either v lightly touching the acc pedal or un-plugging either the MAF, boost sensors to go to basic settings. Both of these sensors are new. the idle and smoke disappear within 10 secs and all seems ok.

The car does not do this when on a cold morning start and does not smoke etc after leaving it for 8 hours just anything upto 6 hours!! It,s not the turbo or injectors as that has been done as well.

Do the CDTI have a idle control valve or something i can try!?!??!?

Please help, the dealers are playing around now and no faults are found...