How do you tune up Nissan Serena diesel engine?

you dont "tune" a diesel. fuel filter, air filter and an oil change only. no spark plugs, wires, cap, rotor..... nothing.

THis is not actually true, but tuning a diesel engine is normally done by remapping the engine management system to allow more fuel into the engine, normally results in more power and torque, normally makes fuel economy worse depending on how much the map is altered, google diesel engine shops or engine remapping. The diesel serena in the uk 1991 -2001 2.3 diesel had the reputation as the slowest car in its class 0-60, 27.8 seconds, therefore i expect it will always be slow whatever you do to it, the later ones were supposed to be better.