Have you had it scanned?
I'd be interested in the live data fuel rail pressure.
This will be running the Ford/Psa diesel engine,so as suggested above,fuel pressure when hot is key.
Thanks both, Given me an idea of what to look for :)
Edited by Leon64 on 26/06/2017 at 11:08
If it uses the same HP pump as the PSA engine there could be a pressure regulator on the back, these can cause that problem on the C5.