Originally Posted by
mudski
Im gonna go out on a limb and say I reckon the intercooler is leaking, being the original from 2004, unless its a fairly new OEM unit, it will be leaking. Also, I'd advise to run a needle valve with the Tilix. This will enable you to control the spool up of the turbo, as sometimes a too fast spool up will trigger false positive overboost limp mode, which could be happening with no needle valve.
So things I would do from here if it were me would be to remove the intercooler and get it pressure tested. If it passes then great, I'd be really surprised if it does. The OEM coolers are known for leaking, even from near new CRD models. Then I would get some MAF sensor cleaner and give it a clean, if you know someone who also has a 3ltr Direct injection Patrol ask to use their MAF for testing purposes. And then put in a needle valve.
Having said all this, it could be fuel related. Blocked filter, air leaking in, or fuel out. You can buy a cheap scan gauge from just about anywhere now, plug this in and when you hit limp mode you should get an error code, then you can see what is causing this..