I have a Mondeo tdci (2002), 188k, with a fault;

Glow plug light comes on, followed by the car going into limp home mode when you accelerate hard. This happens at around 2500/3000 rpm.
It comes up with a generic fault code of P0251 (Injection Pump Fuel Metering Control "A" Malfunction).
Checked & cleaned the EGR & the diapragm.
The car also idles pretty roughly, although at no point does there appear to be excessive smoke.
Any pointers? Thanks for reading.