What would cause a diesel engine to idle real ruff, right out of the blue, on a hot day? Like almost to the point of turning off, then a real ruff recover then the same thing again, just as you start it. If you give it some gas it will idle fine, if you turn it off and turn it back on,the same??

Tired fuel pump? Read Item 6, in the link below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1415281