hello this might help bought a vivaro when i stated it
she kept cutting out until it warmed up a bit,driving it was terrible No power till 2000 revs, then it took off ,after checking fuel filter & air cleaner i replaced them for the sake of £20.00, then the maf air flow sensor from gsf £38.00 that cured it ,I Hope this helps you we have had 2 of these van with the same problem,especially when they have been standing for a while.Also you can try unpluging the airflow senor to see if it makes a differance before hand , as soon as i pluged the new one in it started without and problems and reved up from low revs
Gary, October 2008