I would suggest to do a 100k service and check all your piping.
I used to be lucky if i can get 300km out of my 34gtt while babying it.
Replaced the sparkies, coil pack, belts, oil, o2 sensor, waterpump etc etc....reset the computer and now with babying i can get over 500 a tank (my maths being i was babying it till the half way mark and i did 275kms - not the most accurate but will do hehe)