Elecric Fuel Pumps and Racor Problems

[yellotaxi]

I have a Yanmar 3GM30F with an electric fuel pump and Racor with 10 micron element. The engine stalls after 15 minutes and will restart when bleed. However, when I by-pass Racor engine runs fine. I was forced to do this when on a trip. I noticed that fuel pump was hot to touch when i by-passed Racor.
The whole problem seemed to start when I mustakenly put on 2 micron element. When problem started replace entire Racor with new 10 micron. I am startiing to think maybe the fuel filter is on it last legs and will pump to engine without Racor in-line, but is too weak when there is that added pressure. Did I ruin fuel pump when I had 2 micron element?Ideas?

[seafish]

yello...Just a farmer her with a fix it in the field mentality but aa thought or two.

I think the electric pump is what we would call the lift pump...basically makes sure there is an adequate supply fuel to the mechanical injection pump. It is usually a box the size of a cigarette pack [+/-]. To check that you can turn it on, tick,tick..crack the fuel line and see if it is functioning...not a high pressure stream, just a dribble is about right.

The dying and bleeding is air getting into the system. We sailed from NY to Bermuda on a delivery. After several days of rough seas we had the same problem. Turned out the fuel tank was made with a chopper gun and flakes of fiberglass were getting wedged in the seat of the back flow ball on the top of the Racor. It is a simple system, fuel going toward the engine lifts the ball, if it tries to go in the reverse the ball will seat and prevent the back flow...small pieces of glass were preventing the seating.

The lift pump is inexpensive..check it, if good move back to the Racor. Check all O-rings for air entry....take it apart and clean. You have a Gremlin but it doesn't sound serious, just a pain in the bilge.

Good luck.

[RaptorDance]

The 2 Micron element isn't to blame. If you have to bleed the system repeatedly, my guess is that you have an air leak. Is the gasket on the Racor sound?

Do you have a vacuum gauge in line? what does it say? (we run ONLY 2 micron filters and our vacuum gauge reads zero - if reads over a few pounds, we change the filter).

Regards,
Bill

[seafish]

Another quick thought. At times the hand priming pump doesn't seat well and it will suck air. When you changed the first filter did you hand prime it?

[motion30]

I just had a simular problem with a racor on a trip up the Icw Ran 8 hrs then stalled, same deal bleed the pump changed to the starb filter and was fine Changed filter element and gasket same thing n 4 hrs running ,,stall had some paint chips on the gasket cleaned everything 4.5 hrs running stall Finally changed entire filter ass. problem went away Have not had a chance to put air pressure on the bad filter yet to find the leak but except to find the large quad ring at fault?

[s/v 'Faith']

Here is a quick and easy test to help figure out if you have an airleak after the Racor.

Use the primer pump on the Racor, take a few strokes to pressurize the fuel system from the filter to the injector. If there is a leak, the fuel may seep out once you apply positive pressure.

[never monday]

first,
what model Racor do you have
second.
Where in line is the fuel pump? upstream or down stream from the Racor?

[levm]

I had a similar problem and the culprit was the fuel intake from the fuel tank. After a long trip or rough weather the sediments which accumulate at the bottom of the tank are clogging the screen of the fuel intake inside the tank. The solution was cleaning the screen of the fuel intake and all worked well.
A good indicator for this problem is right after the engine shuts down loosen the Racor cover, if you hear air coming in to fill the vacume in the fuel line it is most likely a problem at the fuel intake.

[DeepFrz]

levm, I would remove that screen from the pickup tube if I were you. The problem you had will happen again. The filter should handle the filtering, not a screen that is hard to get to and hardly ever checked.

[daddle]

I had , a dozen years ago, a new Racor that was painted inside and out. The paint on the filter mounting surface wrinkled, peeled, and flaked. Could not see the problem initially. Caused an air leak. Racor had some QC problem I guess, the new one wasn't painted inside.

[keepondancin]

Similiar problem years ago. Took the racor completely apart and found sealant crumbs in the intake elbow. The sealant was from previous owner using silicon to seal inspection port on tank. The crumbs clogged the intake to the racor, and the suction of the fuel pump was stronger than the seal on the racor, and would draw air in. 10 years later it is still good.

[Chief Engineer]

Yeah Silicone and diesel is a no-no of the first degree.