Re: Diesel Bleedback - HELP
I had a '89 F250 truck with a 7.3L IH diesel so from that experience all I can suggest is that you still have air entering the fuel system somewhere. That's if the IP isn't on it's way out. By bleeding the system do you mean before the injector pump? if so, and that consistently cures the problem then that seems to suggest air is getting into the lines before the IP. If it's a mechanical fuel pump, try putting a gauge on the output side and monitoring how well it holds pressure. If it doesn't that consider that a source of the problem.<br /><br />Of that era, most injector pumps want positive pressure fuel supplied to them, around 6 psi. They will, or at least mine did, would pull fuel if you didn't supply it with fuel but it is not good for the pump and can lead to failure. Unless I misunderstand you, supplying fuel via a 5-gal drum to the IP isn't a good idea and also doesn't tell you much. Another common source of air entering the fuel system is at the injector caps. A solution to this, more of a work around actually, is replacing the mechanical fuel pump with an electric one. That will force air out of the lines quicker than a mechanical pump if the air leak is small. hope that helps some, if all else fails fork up the cash for a new IP, if the boat has a decent amount of hours on it (it's 20 years old) then your probably due for an IP anyway.
