missfire and grey smoke 1750- 2200 revs

hello have seen this problem on a few threads but does not seem to be a answer is there anybody got to the bottom of this runs fine a bit sluggish to take of then runs ok but about 1500 revs onwards at tickover starts to missfire and emits grey blue smoke egr bypassed crankcase filter changed getting near to mot so need to sort no check engine light on so may be this would rule a few things out does start and tickover fine

get it on a computer and cheak codes i had a similer problem and it was low fuel pressure
http://www.landyzone.co.uk/lz/f9/latest-my-freelander-202759.html