Hi Steve, What seems to be the problem ?.If it cranks but not starting,oil stainer issue as you mention is checked by adding 2 lts of oil from max line, if it starts the strainer has split.The next thing is the injector wiring from the head are all the same colour, but Loom side there is a wire in the centre which started life yellow ,but is probably now white( high pressure oil rail sensor signal) if you cut it the E.C.U.
reads the open circuit as full rail pressure. It would then start,but would be gutless unless you drive it once engine is warm, switch off,then ign.on and bump start it in motion and power comes back. The cheapest sensor is through Vauxhall not isuzu at about £72.00.I can give you part number if req.The multi plugs are probably full of oil ,New engine side harness is £104 from isuzu(cheaper than Vauxhall).There is loads of info on www.itoc.co.uk. It is free and there is a guy on there called Eithan who works at a Dealer who knows these like the back of his hand. The importers( International Motors)
are still supporting issues from 10 years ago.There was an injector issue late last year and providing the vehicle is in the injector batch number they are still changing them F.O.C.
and that is a good time to supply sensor and harness as the dealer will fit them F.O.C.whilst doing the injectors.You can check with any dealer or I.M. that all recalls from 1998 have been done and if not they will sort.