6.4 Acert Cat Fuel Return Flow Testing

[@Rainyoni288]

Why return fuel is verry hot, derate, and no start...?

[@colemanmech]

Do you have any way to measure your rail pressure? It sounds almost like you've got a restriction, restriction with high fuel flow, will create heat. It's possible that you may also have a large internal leak, but I'm not sure if that would cause heat...