I have a 1.7 CDTi Astravan MK4 (2005 54 Plate)
When you pull up at a junction and let it idle it is smooth at first then it becomes lumpy, between about 750 rpm and 900 rpm. The van doesn't really lack power although if pottering around town it is not very smooth, hunting slightly and if you accelerate or de-celerate it is not that smooth.
Reading various posts on here points to the MAF sensor. I disconnected this thinking it would bring on the light and if the MAF was at fault smooth out the tickover. It made no difference and didn't even bring on the EML light (this being on the drive ticking over for a few minutes and being revved a few times).
It has 61000 miles on the clock and the EML light works.
Can anyone shed any light?