Hi Mark,
I have had the exact same problem about 4 months ago. Renault said there was nothing wrong with it because the computer said so?!!!
It now wont idle properly when cold and the airflow meter was the only thing to show up as faulty. New air flow meter fitted and goes like the wind, really smooth but still wont idle properly and wont rev untill engine sorts itself out after about 1 min.
My advice is take it back to Renault and DEMAND them to investigate further before you end up in my position and it costing you a lot of money to get it sorted.
What annoys me is that i am sure that Renault know there is a common fault but will not admit it.
So far van not fixed, and costing me more money than it is worth through loss of earnings. Will let you know the outcome.
Steve
November 2009