Fuel pump question

[Alan Wheeler]

Probably due to a higher flow rate while you bleed it, than normal flow rate, has caused the check ball to close.
As Pat said about the engine lift pump, the best action is to either stay with the mechanical lift pump, or take it completely out of the line. The mechanical pump can stay there pumping nothing, it won't cause any problem.

[sneuman]

Well, I replaced the fuel pump, but in the end I think it was the filter and simple vapor lock. As BMYC suggested, the check valve in the Racor must have gotten bumped during filter replacement. That was part of the problem. Then it was just a matter of bleeding the rest of the system.

Thanks all.

She's purring like a contented tabby now!

[MitchM]

""Mitch,
Running an electric fuel pump on a GM series Yanmar is asking for a failure. The GM uses a mechanical diaphragm fuel pump. These leak quite often. If you push fuel through it the fuel can fill the crank case.
__________________
www.inlandmarinediesel.com"




Hi NeverMonday, (great name wish i could get that kinda job ) thanks for your comments . sorry for the confusion---i do NOT have my electric diesel
pump wired into the fuel system for the yanmar which indeed is a mechanical lift diaphragm pump ( that seems to pump 1/4 teaspoon per stroke when you are trying to bleed the fuel system.... i have my diesel pump wired to a removable board behind the engine compartment to use as a polisher to push fuel from tank 1 to tank 2 and run it thru a 30 micron racor, and also as an offshore auxiliary jack pump to pump fuel from a portable tank into the fuel feed tube without slopping raw fuel all over the cockpit.(stupid place for an inlet feed tube especially in 8 ft seas.) my electric jack pump wired to a board a very handy little thing to have onboard.
for purposes of getting better 'lift' out of the mechanical pump when i am priming the fuel system on the yanmar, i have installed a squeeze bulb after the racor and before the secondary small on-engine filter.. works like a charm.

[never monday]

Squeeze bulbs do work, but they can cause air leaks. The mechanical lift pump is sufficient to bleed the system. Once the siphon is established with the vacuum.