[Luccia at Pelican Parts]

Definitely check timing. Also, how many miles are on your R56 and have you ever done a carbon clean up? Have you ever had the HPFP replaced?

http://www.pelicanparts.com/techarticles/MINI_R56/88-ENGINE-Turbocharged_Engine_Carbon_Cleaning/88-ENGINE-Turbocharged_Engine_Carbon_Cleaning.htm
http://www.pelicanparts.com/techarticles/MINI_R56/94-FUEL-High_Pressure_Fuel_Pump_Replacement/94-FUEL-High_Pressure_Fuel_Pump_Replacement.htm