I go through and explain how I bled the fuel line on my engine, a 1986 Yanmar 3GM30F diesel. This winter I had started to drain the Racor to replace the fuel filters and then changed my mind and decided to do it in spring. I forgot to close the Racor top vent and so when I went to start it, all that air went straight through the fuel lines. It ran for about 57 minutes and then died. So, I had to bleed it all out. Thankfully, I was able to get it running without having to crack the fuel injectors.