I pulled out the cold start and fired her up but the revs were up and down for a bit. I used to have a petrol saxo that went like that at one stage due to on the butterfly. Do you recon this is the diesel equivilent?
Just one idea: I recently had my 2.5TDi Syncro spluttering and jerking under accelaration.
It was the diesel fuel filter perished- as you stand infront of open bonnet just look down to your right, up against inner wing. Mine was renewed, and now leaping for joy and urgency. I thought the remap was corrupt, but as Jabbasport said, it is normally the simplest of components cause most headaches.
Maybe worth a look?