David, on a couple of different engines. I've had the electric fuel pump fail intermittently. While bringing my Sabre home the oil pressure would drop off randomly and the engine would bog down also randomly. When both happened at the same time I began to panic that the engine was thinking of going south. The boat had been sitting for 4 years. I pulled into the closest marina did an oil change, no filter change. That helped the oil problem. As for the fuel issue. When the electric pump got warm it would quit pumping fuel. Let it cool and all was good for awhile. To get home I ended up putting a fuel can in the cockpit running a hose to the Racor and a return back to the Jerry can. It was a very accurate way to see fuel burn. New electric fuel pump all is well. Had the same symptoms on my hot rod truck with an electric pump. I had been told by my broker when I bought her that the oil had been changed. I don't think it was. Changed the oil and filter again once back in my slip, and all is right with the world. Good luck.
Douglas Mountjoy 1988 C&C LF 39 Mexico at large 1984 Sabre 34 Port Orchard, WA On Tue, Jun 27, 2023, 09:45 David Knecht via CnC-List <cnc-list@cnc-list.com> wrote: > So I am back to my engine problem hoping someone can help clarify things. > I have had the engine quit several more times, but with no consistency as > to when or why it happens. We were on a cruise recently and used it often > and for long periods going in and out of harbors. Mostly it worked fine > but had it stall several times: start and run for a few minutes, then > stall, restart then stall, restart then stall, then run fine for 20 min or > more. This happened in two separate situations a few days apart but no > stall several other times. In all cases, it has eventually restarted and > ran for extended periods. These intermittent problems are the hardest to > diagnose in my experience. This seems most likely to be a fuel related > issue so now I am trying to fully understand the fuel system. > > I installed a Racor 500 unit last summer with a T-handle vacuum gauge on > top. Fuel goes from the tank, through the shutoff lever to the Racor, then > to the fuel pump, then to the secondary and on to the engine. If I > understand this correctly, the gauge on the Racor unit will measure > restriction in the fuel flow upstream of the gauge, ie the primary (30 µm > in my case). I know the gauge works because if you partially shut off > the fuel lever, you see the gauge gradually increase in vacuum reading. > But it seems that it will not tell you if the secondary is plugged. > > 1. I don’t see how the secondary (10 µm in my case) could be plugged if > the primary is fine but I guess not impossible. My temptation is to > replace the secondary since the primary is not showing any sign of being > plugged (from the gauge), but I don’t see how this could lead to an > infrequent intermittent stall. > 2. Fuel pump problem (loose wire etc.)? You can hear the fuel pump > running when the engine is off and I have never heard it stop or pause. > Can fuel pumps fail like this? Can that lead to an intermittent stall? > 3. Air getting into fuel line- seems possible, but I don’t see how that > can be the cause if the engine runs for an hour continuously once restarted. > > Any ideas welcome! Dave > > S/V Aries > 1990 C&C 34+ > New London, CT > > > Please show your appreciation for this list and the Photo Album site and > help me pay the associated bills. Make a contribution at: > https://www.paypal.me/stumurray > Thanks for your help. > Stu
Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at: https://www.paypal.me/stumurray Thanks for your help. Stu
