Car was standing for 3 weeks, started OK and driven a couple of hundred yds, turned off and left for 24 hrs then started again today and another short drive (checking for brake noise).  This time when I tried to turn around I couldn't reverse due to lack of power, I had to gradually bring the revs up high as poss, then slip the clutch.  It started and idled OK and no dash lights I parked it up and it seems OK now.  No new codes just the 10807 (turbo boost pressure) which has been there for the 5yrs I've owned it.it must be fuel related but it's not due a service/filter.

Any ideas?

Are the brakes binding?

boost valve not working? check the vac pipes also could it be bad diesel.

The next things are MAF sensor or MAP sensor clean