My 1998 V70 TDI which has done 140K miles generally starts/drives well and on town/urban driving is currently doing 33mpg(uk) this creeps up to around 40 on the motorway.
It passed it's test last year so the emissions must be OK.
If I accelerate hard either from stationary or put my foot down when travelling I leave a big cloud of black smoke behind me.
I have had number of suggestions, needs new injectors, injector timing, sticky or stuck EGR valve.
While I can do most work myself I struggle as an owners workshop/repair manual was never published in the UK.
Any help advice would be appreciated.

Just edited and added this, have looked at the emanual link at the top of this page and asked them if the V70 manual covers UK models.

 

Mmmm I guess I am on my own!!

 

A good thrash about once a month never goes amiss on these. Clears the "cobwebs" out if all you do run around town. I worked at a dealership and all phase 1 TDIs have a tendency to cough out black smoke under hard acceleration. All we used to do for an MOT was give them a "good ragging" up the road for 5/6 miles before emmisions test and they would "sail through" try testing before a "good ragging" and they would fail EVERY time!!!