Only help I can offer is a downloadable version of the manual.
Go to www.gmail.com and log in as isuzunz password 4jb1turbo
Click on all mail
You will see 11 emails for a trooper 92 onwards
Download the attachments from these emails and also get a copy of 7zip from a free software site
Put the attachments in the same place on your pc and use 7zip to open the part1 file. This opens all the files into a pdf file you can save and open with adobe Acrobat.
This is the only manual that covers your engine but you might also want to get the 8 Frontera manuals as well as they cover everything else on your car.
Another thought is to look up the south african isuzu club. http://www.isuzuoffroad.co.za/index.php
They are a lot closer and easier to deal with if you need to find parts localy