Hi, The pictures help a lot to understand your fuel problem.
I see you have a three cylinder while my Universal is a four. I can only advise on my system. I changed the 13 year old electric fuel pump when I got the boat and replaced all the filters 18 years ago. I replaced the fuel filters twice before realizing Parker recommends they be changed after 500 gallons. I keep my fuel clean by using plastic diesel jugs to add 5 gallons at a time. I race so I don't keep the tank filled unless I'm cruising or taking the boat a far distance. My boat: The fuel circuit starts at the fuel tank where there is a shutoff valve, the suction hose goes to the Racor, then the electric pump, then to the secondary filter, to the injectors, and there is a return hose from the throttle (fuel rack) that takes any unused fuel back to the tank. All of my fuel lines are fuel rated black rubber hose. The pump pulls fuel from the tank through the Racor (30 micron) and then pushes it through a secondary filter (10 micron) and I never need to bleed the lines. The pump circulates more fuel than the engine needs so any air gets pumped back to the tank. If you keep getting air in the lines, you must have a leak between the suction side of the pump, the Racor and the tank. From your picture of the Racor, I wonder if the fittings are proper. Yours look to be compression fittings. All of my connections are barbed with a stainless hose clamp around the rubber hose. Stupid question: Are the fuel shutoff valves open at the tank? I think the quickest and cheapest fix is to replace the entire suction fuel line between the pump and the Racor and all the way back to the tank. New hose ($2.20/ft) and maybe fittings too, will be a lot cheaper than replacing other components. Next I'd replace the Racor filter at $60 or maybe replace the whole assembly at $99. I'd replace the pump which will cost about $150. If I were doing it, I'd look at the age of the rubber hose and components and replace anything older than ten years. The fuel lines are run together, so you might as well replace both while you have the floorboards up. That will give you most peace of mind and I'd buy Marine rated fuel line that is labelled as such. Last thought: since you have an electric pump, consider pumping the old fuel out of the tank into gerry cans and giving away to someone with oil heat, and replace the fuel with fresh diesel from a very busy truck fueling station. Add Seafoam and Bioflur if desired. Chuck Scheaffer, Resolute 1989 C&C 34R, Pasadena Md > On 10/05/2020 10:32 PM > > General Gao <general.z....@gmail.com> wrote: > > > Reporting back to my findings for today: > > This picture shows my primary filter? > > > https://drive.google.com/file/d/18tYO70bg6tTpVEifQGlXSI1ucYuvgLDq/view?usp=sharing > > this picture shows the air in the tube out of the filter: > > > https://drive.google.com/file/d/1bIr2NuR6K9nEYbwYj36OKaR4umeI2dsK/view?usp=sharing > > this picture shows the bleed valve: > > > https://drive.google.com/file/d/1umfxt0UbC81YrAxemHWuBGX3M3U-I-3V/view?usp=sharing > > When I turned on the fuel pump, the click sound was heard; I could see > the fuel in the tube move with the sound of fuel pump clicks; if I open the > bleed valve, fuel will come out of the valve in the rhythm of the fuel pump > clicks too; also, the fuel pump click sound is with faster pace if I keep the > bleed valve open. > > I am having a hard time to understand why when there is so much air in > the fuel, I still have fuel pumped out from the bleed valve at the fuel > injector? > > I will continue to check the fuel lines. Now I remember that, while I was > trying to figure out what was going on, my wife mentioned to me that she saw > air bubble going from the filter side to the engine side... > > On Mon, Oct 5, 2020 at 3:01 PM General Gao < general.z....@gmail.com > mailto:general.z....@gmail.com > wrote: > > > > Brian, the diesel in the tank would be a couple of years > old. We put diesel treatment every season in it though. The day before this > happened, I added 24 liters of diesel in the marina. > > > > Bo > > > > On Sun, Oct 4, 2020 at 6:47 PM Brian Davis < > > brianwdavis...@gmail.com mailto:brianwdavis...@gmail.com > wrote: > > > > > > > How old is the diesel in the tank, and have > > you ever had the tank polished? > > > > > > When I recently rebuilt our Yanmar 3qm30, I changed every > > > hose and rebuilt or replaced all fuel and water pumps. > > > > > > I also had a guy come out and polish the 30 gal tank. That > > > process was cool and involved him pumping out the fuel to a filter pump > > > and then shooting it back in the tank aiming at the corners, etc. At the > > > end, I had him completely pump out everything and dispose of it. (Cost of > > > about $325) When I added the fresh diesel I also put a can of Seafoam > > > from the auto parts store which is great stuff for diesels. Then, priming > > > and bleeding took a while. But after I bled the air at the big fuel > > > filter and then the small filter on the engine, I disconnected the three > > > fuel jets going directly into the head. Then I cranked it until fuel > > > squirted out of each jet. Be sure to put a bunch of paper towels in front > > > of each jet. That will help you know that fuel is coming out without > > > making a big mess. She runs like a champ now. > > > > > > I've read the old diesel can grow fungus and of course gunk > > > or water in the fuel can make the engine stall or sputter. > > > > > > Brian > > > S/V Nina > > > 1980 Landfall 38SL > > > > > > > > > On Sun, Oct 4, 2020, 5:45 PM Josh Muckley < > > > muckl...@gmail.com mailto:muckl...@gmail.com > wrote: > > > > > > > > > > It is unlikely that fuel line > > > down stream of the lift/priming pump is leaking to the extent that air is > > > getting in since this section is under pressure. I would look upstream > > > of the lift pump. This section is under vacuum. The upstream fuel > > > filter (not the one mounted on the engine - often made by and referred to > > > as "the racor") is very likely to be the problem. The rest of the > > > fittings and connections rarely get disturbed but the racor does. Some > > > racors are difficult to fully bleed and ALL of the interfaces which are > > > disturbed during filter changes should be suspect. > > > > > > > > Rule that out and then we can talk more. > > > > > > > > In the mean time check out these videos for fuel > > > > bleeding and racor mods. > > > > > > > > https://youtu.be/F7KD1_EZmU4 > > > > > > > > https://youtu.be/H-GI38vE4hQ > > > > > > > > Josh Muckley > > > > S/V Sea Hawk > > > > 1989 C&C 37+ > > > > Solomons, MD > > > > > > > > On Sun, Oct 4, 2020, 17:24 General Gao < > > > > general.z....@gmail.com mailto:general.z....@gmail.com > wrote: > > > > > > > > > > > > > Hi everyone, > > > > > > > > > > Again, looking for advice from experienced > > > > > sailors. > > > > > > > > > > Today on my trip, my Diesel engine stopped > > > > > frequently. The last time it stopped by itself was because air in the > > > > > fuel line. I did do some more than “usual” heeling today but the > > > > > engine ran about 2 hours after that without issue before this fuel > > > > > line issue started. I checked the bleed valve, could see that after a > > > > > few seconds the fuel came out, so there was air. The problem was that > > > > > even after this, the engine still stopped working due to fuel supply > > > > > issue like every 5-30 minutes randomly. Each time I did the bleeding > > > > > there was air. > > > > > > > > > > How can this be? Where should I look? > > > > > > > > > > Thank you in advance. > > > > > > > > > > Bo > > > > > _______________________________________________ > > > > > > > > > > Thanks everyone for supporting this list with > > > > > your contributions. Each and every one is greatly appreciated. If > > > > > you want to support the list - use PayPal to send contribution -- > > > > > https://www.paypal.me/stumurray > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > Thanks everyone for supporting this list with your > > > > contributions. Each and every one is greatly appreciated. If you want > > > > to support the list - use PayPal to send contribution -- > > > > https://www.paypal.me/stumurray > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > Thanks everyone for supporting this list with your > > > contributions. Each and every one is greatly appreciated. If you want > > > to support the list - use PayPal to send contribution -- > > > https://www.paypal.me/stumurray > > > > > > > > > > > > > > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > >
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