injector pump/air intake issue

[LRover74]

Got a question for diesel people.
My engine starts easily and idles fine,however after increasing rpm it has a flat spot accompanied by black smoke. In other words increasing the injector trottle shows no increase in rpm.The question is how do you tell if it is an air intake/turbo issue or an injector pump fault? Thanks

[Jim-ME]

My guess is that you have some sort of restriction in the air intake so you aren't getting enough air to fully ignite the fuel. I don't have a turbo on my engine but the only time I've ever blown black smoke with my NAD was near the top of Mnt. Washington. I my be wrong but it was chalked up to thin air.
Jim

[superstator]

Yes, black smoke in this case means there isn't enough O2 to burn the fuel being injected. Sounds like a burned up turbo to me, unfortunately. Which engine?

[LRover74]

It is a nissan,not sure of the exact engine. I am working on trying to fit it in the rover. What you are suggesting if that the turbo in not spinning or the seal is gone.What is a good way to test this? Thanks.