check the 4x4 engages ok, theres a button on the dash which should show a solid green light once its engaged....if it keeps blinking then its not engaged and obviously theres a problem which could be an easy fix by changing the vac pipes but ofc could be something much more serious. get underneath and check the rear chassis crossmember ( its tucked up behind the rear bumper) they are prone to a bit of rust . anything else treat it & check as you would a normal car.
fuel pumps are known to possibly fail which can be caused by running out of fuel so keep it well topped up, they are quite expensive to replace ( especially more so the later registered models )
good luck
