Guys - here's one that has me head scratching. I think I've got some air in the suction side leading into the fuel filters - 5psi on start up and then drops to 0 psi. The engine is a 3208 NA 210 hp (4000 hrs). The 200 gallon tanks are pretty low(60 gallons between the two sides on the sight glass) When coming across the bay, the engine lost power, the tach began to wander and then the engine died. I put the Admiral on the helm and was able to get it started and back into port by pumping the priming pump continuously to pull fuel into the lift pump.
It seems like it is out of fuel despite what I see in the sight glass(yup, I opened the sight glass valve!) I'm old enough to have done some shade tree mechanical but I'm no diesel mechanic. In the gas engines I have some experience with, there would always be a low pressure fuel pump delivering fuel to the carb where it was atomized. Does the diesel lift pump provide low pressure suction of fuel from the tank AND high pressure fuel delivery to the injectors?
Does a low fuel condition make t more difficult to get fuel to the lift pump?
Today I changed all the filters, and tomorrow I'm going to attach a small pump to the tank/primary filter line to confirm fuel flow from the tank and that the pick up isn't clogged. Then I was going to pressurize the line between the primary filter and the secondary on the engine and see if there is a pressure drop anywhere along that line. Other ideas/suggestions?
What would the symptoms of a bad lift pump be?
Thanks for any/all info