engine hesitation/power loss

Hi All ,
Has anyone experienced this , it only happens when warm and has been running for a while , when I go to accelerate away from a e.g. junction I apply the usual amount of throttle and the disco appears to hesitate/suffer a drop in power as if it will stall , so I dip the clutch temporarily give it a bit more throttle and she's okay

Any ideas ?

Alan

What engine you got? Petrol v8 I'm assuming....

No, its a diesel.

blocked fuel filter, weak fuel pump, oil in injector loom, sticking wastegate or solenoid, faulty egr valve, faulty throttle potentiometer, eratic maf sensor.

is there any smoke when it happens? if so what colour?