Later coil packs can give problems, normal coil problems would be engine management light on engine lacking power, may be stalling and sounding like a lumpy sewing machine (see picture). Test with spark tester, see misfire.
Try banging the bottom of fuel tank, worn fuel pumps can stick, replace asap.
Sudden loss of power may be after going uphill, check turbo charger pipe has not blown off, it is located next to turbo on top of gearbox.
TDCI engines can start smoking (black smoke) and loose power due to EGR (Exhaust Gas Recalculation) valve sticking, try removing pipe or connector and then gently tap valve to get valve to close, you may need to leave disconnected until valve is replaced(see EGR page), this will leave Engine Management light on.
Later Ford's measure the temperature of the metal as opposed to the coolant, if the engine overheats the computer will shut down the engine to prevent damage, but if the sensors goes faulty (e.g. In the red) the car will not start or stop.
Later Diesels are fitted with DMF (Dual Mass Flywheels) flywheels.
These are two flywheels joined together by springs and dampers to smooth out vibration, however they wear and under load they distort, moving the flywheel away from or hit the CPS (Crankshaft Position Sensor) losing power and maybe cutting out, the vehicle will probably then restart as normal, a new and expensive flywheel is the only cure.