Renault t 460

Hi guys , we are having a problem with one of our Renault t 460 where upon start up and releasing the handbrake the engines dies , sometimes stalling completely not all the time but occasionally, driver feels the power in the lower rev range is not what it used to be , anybody suffer anything similar?

Some of the large stock piles of these 65 reg t range 460s mid lift units that are £20,000 are getting sent back to France to be stretched and made in to rigids to include 9 tonne front axle and made in to rear lifts new diff not sure about the gearbox but on return to the uk are £40,000 with drive line warranty, anyone bought one ?