bomas

Hi, I have bought a 1993 xantia 1.9d lx on ebay for not very much. It is in very good condition but it has no power or acceleration or torque.It starts up every time without a problem and idles correctly and does not smoke. I have big lorries overtaking when going up hills.Where do I start looking for the problem. Is it injectors, timing, pump or elsewhere? Your help would be much appreciated.