I've got a 1.8tdi 2008 ford focus titanium diesel with an intermitant fault,On a few occasion it stalls and cuts out.When I try to restart the engine it just cranks over but will start,I've had the AA out who have plugged into the car but it comes up without any fault codes.
It's not the immobiliser and the only thing I can think it could be is the fuel pump.
My question is how can I check the fuel pump/fuel shut off valve when it won't start? When it does fire up it starts up as if nothing was wrong.

Del, July 2014

On modern motors it is very difficult to determine what causes faults like yours,it could be electrical or fuel related,crank sensor may be worth a look and I take it all your filters are up to date and renewed regularly,did have one of these with intermittent bad starting and it was a wire rubbed through on the engine loom down near the injectors, these would be worth looking at but guessing may get you nowhere and cost money and it may in the long run need to go onto Ford IDS which will have an in depth look at what all your sensors/fuel system/EGR valve are all doing, good luck.

cdc, July 2014