I have a 99 powerstroke that has trouble starting when warm. It runs fine after it starts. It will always start right away when its cold. My oil is up and I put in a new fuel filter,could it be my transfer pump.

. Change the air filter (Motorcraft FA-1680). It should be changed every 5,000 miles. Diesels require plenty of air.

. Remove and fully charge each battery.

. Clean battery terminals and connectors; apply dielectric grease; ensure connections are tight.

. Read link below for additional ideas:

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