My Defender 110 TD5 2003 model has a rev problem as follows. At standstill it will easily rev to 4000rpm +. But once driving, I can't go over 3000rpm (even on a slight downhill). I have new injectors, new turbo, bigger intercooler, tried various ECU maps but currently back to standard. Power and torque to 3000rpms are just fine. Any advice will be appreciated.