dump out the diesel in that, then fill it with Seafoam to the brim. Run the engine for about a minute, enough to get that Seafoam into the engine/injectors. Then I shut down the engine and leave it off for 24 hours or so. I have no idea if it works. I'm hoping it cleans the injectors, etc. I do this once/twice a season. Others simply pour a can of the stuff into their diesel tanks. Cheers, John