Honda Accord - hunting - Chris Honda Accord

I have a 2007 Accord saloon 2.2 ctdi with 50,000m and am finding fuelling patchy in cruise - can at times feel like a vehicle does when it's runing out of petrol (or diesel). Seems to happen around the 1,750 rpm mark, any gear, but only when 'criusing' (clears instantly when you call for power and behaves perfectly normally in an acceleration mode). The vehicle has always suffered from marked 'pinking'/ diesel 'rattle' which may be contributory? Any thoughts or suggestions welcome.