Outer Limits 4x4 Board

i have a 97 HZJ75 with a 1HZ diesel motor.
it will not go over 1400rpm. the throttle seems to be fine, new fuel filters - no restrictions. has been bled - no air in the system.
i was wondering if there is an internal strainers or a common problem that someone has come across before.

Put a clear line on the return line, if there are bubbles it is getting air in it. if not, fit another fuel source to the inlet of the pump, does it rev freely now? If not you have a pump problem or a lack of air in to or out of the engine.


Andy