i have a 15p 2003 (165,000miles)td5 discovery that has never rev'd up all the way it would act as if there was a limiter at 4000-4250 when standing still and then 3250 sometimes when moving as if its struggling it would jump kinda
i have rebuilt the pressure reg with a bosch kit to try solve it also tryed a genuine pump and done injector seals (not sure if it has anything to do with it but did the seals about a month ago and already seem to if failed 3rd time i have done them (all were allmakes4x4) )
the head dosent look cracked and no diesel in the oil
not sure what to do next to try cure the problems