ford focus 1.8tdci 2002 52?

my 02 plate of same model has started doing exactly the same, out of the blue engine just goes off, all indiacations seem to lead to camshaft postion sensor, which, i hope it is because im trying to find one to fit to car........car drives really well and am getting 52 mpg, sluggish at starting...which again points to cps.
will let you know how i get on

worried
June 2009