I don't know about Alaska either, but as the owner of a 300D Turbo for 17 years, I can tell you that in Virginia they run slow until they warm up. It is the nature of diesels - combustion efficiency is partially dependent on engine temperature. Ours got slower as it got older and lost compression. It got a boost when the injectors were replaced.
My recommendation is to do a compression and leak down test and check the injectors.
Falls Church VA