1.6d 2009 slow start off

[Mylli]

Hi All,

I'm a new volvo owner driving a 2009 1.6 d s40. I have had the car fully serviced and the rear main seal fixed that was leaking. Since I have had it i also had injector 1 3 and 4 refurbished so I do try look after it but I've noticed it needs a good rev ie over 2500 to give any confidence in picking up speed joining traffic. On motorways the acceleration seems fine it's just that initial start off the line that feels slow and sometimes dangerous. I also have a 7 seater c4 grand picasso and that car has no issues getting off the stationary position and up to speed and my mechanic said they have the same engine. I use diptane in it at every fill. Any help would be appreciated.