p38 diesel , irratic idle

hi guys ,
im hoping someone on here may have had this problem before ,
a couple of times lately my motor has been idling irraticly , hunting you could say , one minute it idles fine then its up and down , today i came to a junction and it started doing this again , so i blipped the throttle and it revved up then cut out , the strange bit is no warning lights came on , the low fuel light came on but was still above the empty , so i put 20 litres of diesel in and all seemed ok , then about 10 miles later at traffic lights it started to hunt abit again ,
any one had this problem or any ideas what it maybe ? possible fuel filter? intank pump/level sensor?

Any help would be great , cheers guys

If the fuel filter has not been changed recently it would be worth changing that, also do a current check on the in tank pum to make sure it's working.
Otherwise, get the faults read, it could be a dodgy sensor.

Is it a manual? Check threads on DMF / dual mass flywheel. If it`s that it`s a purely mechanical fault & there`s no track in the electronic memory. But the fix is time consuming & expensive, so do as Datatek suggests first.