Diesel Engine Power Loss

Ever since I went on a very dusty trip a while back I have had an issue with the engine in my Ninety lacking power - particularly at high revs. It now struggles to get up to the speed limit and feels like it is being held back by something. It was exhibiting a symptom of surging also.

I replaced the air filter and gave the air box a good clean out after the trip but that does not seem to have solved the problem.

The engine is a naturally aspirated Nissan LD28 straight-six diesel. It's very basic with no electronics - like the N/A Diesel from Land-Rover - so I'm sure that the same principles will apply in finding and diagnosing the issue.

Can people give me some suggestions as to possible causes of the loss of power and how to test for them? Does it seem likely that the dust is the culprit here?

Thanks all.

I'd change the fuel filter too and maybe try to clean out the fuel lines, undo them at each end and blow them out with a compressor air line. Similarly, check the distributor isn't clogged with dust, that the radiator has a free flow of air and all it's fins .. especially if it appears to be running hot.

A decent full service might help!