My understanding is that the lift/low pressure pump on the Yanmar is integrated into the injector pump and that the priming pump (I carry an extra) is separate. I am basing this on the Yanmar 4JH3 HTE Service Manual and the Parts List. The shop manual shows the "feed pump" as integrated and the parts manual doesn't show a separate part, only a priming pump.
There was an earlier post about the need to replace the low pressure pump on a scheduled basis (that it would not supply fuel at an acceptable rate) but it seems that would entail replacing the injector pump or a component of the injector pump. Does anyone have a clarification on this?
