Hi, first of all sorry for my bad english! I looked for manual about "how to read off the ecu" and found your posting!
If you´re looking actually for a solution check this site WorldWideWeb.meckisfaq.de/viewtopic.php?t=345&highlight=diesel (Sorry, it wasn´t allow to post the complete link! please change WorldWideWeb into www)
Problem should be that the 1Z hasn´t a fuel consumption pin! You need do generate this signal for your onboard unit!By the way in germany they call it BC or BordComputer!
I hope I could help you! Sorry for my late answer! Greetings from Germany!