Generator fuel problem

[Bare Necessities]

Recently soon after cranking my gen it quit. I began making some checks and discovered my engine mounted fuel filter (secondary) was dry. I figured it needed changing anyway so I changed the secondary filter, filled it with fuel and she started and ran as it should for a few minutes, 7-8 minutes, but then died. So I figured the primary racor filter is the problem. Changed it, filled both with fuel and it ran till dry. I thought well it has to be my lift pump. I ordered a new lift pump, installed the new pump but still the same thing, run till dry and quit. I changed my selector valves from port to starboard tank for fuel supply. Still the same. I ran a line from the supply side of the lift pump to a gallon jug and it runs perfect till it runs the gallon jug dry. I now know there has to be a plugged line or a cracked line allowing it to draw air instead of fuel. My next process of elimination I think should be to hook a temporary line to the tank side of the racor and see if it will run. If it does there has to be a problem between the racor and the lift pump. Am I thinking right? The line is under and behind the gen hidden from view but the temporary line should tell me if that line is the problem? Anyone want to weigh in and change my mind. Thanks, Charlie

 

[psneeld]

I have a 1988 Westerbeke 8BTD.

A loose wire on the on the exhaust overtemp safety switch was shutting down the genset.

Before I discovered the wire, I was focused on fuel lift pump as the fuel filter was empty of fuel each time I checked it after shutdown.

Not sure exactly how I was losing power to the lift pump and not the fuel solenoid.....thus the fuel filter running dry....so It took a couple days chasing my tail to figure it out.

Check to see how your pump is powered and if a shutdown sensor could do the same thing in your case.

 

[Bare Necessities]

Thanks for your input. My gen is a 1989 Yanmar engine equipped with a mechanical pump (non-electric). After hooking the lift pump to the gallon jug and seeing it run flawlessly on the gallon I was still undecided. But I think in my case it has to be a clogged line or broken line between the lift pump and the racor allowing it to pull air instead of fuel. What has me puzzled is that I would think if it is a broken line I would have at least a small fuel leak also. But I will look more the next time I get to go to the boat. Thanks

 

[Lepke]

If you install a vacuum gauge between the Racor and lift pump it will tell much. High vaccum is a clogged filter, line, pickup tube. Low vaccum, sucking air if no fuel. Mine reads almost zero with a new filter and when I change it at 500 hours it reads about 7" of hg.
If you install an electric fuel pump inline it makes bleeding, changing filters easier. About $10-20 on ebay.

 

[DavidM]

Sure sounds like a totally clogged fuel line or more likely an air leak. Check the Racor for proper assembly last time you changed the filter and tighten all fuel line connections and see if that doesn't solve the leak problem.



David

 

[Bare Necessities]

Thanks yo both for the two new responses. My son agrees on the vacuum test. He has one that I will be able to use when I go back to the boat. The gen problems began before I changed either of the filters and the symptoms hasn't changed even after changing both filters and the lift pump. I would install an electric pump but it bleeds itself of air easy if it can get fuel. Thanks again for the suggestions.

 

[Captain Ralph]

How low are your fuel tanks. Gen sets usually have their own pick up tubes mounted higher than the engine pick ups.

 

[Bare Necessities]

Both tanks are 3/4 or more full. I have ran the gen with a lot less fuel in the tanks. I thought about the pick up tube possibly coming off but it will not run on either tank. Thanks for the suggestion, Charlie

 

[Shrew]

Moved thread from "How To Use The Forum, Site News & Account Concerns" to "Power Systems"

 

[Bare Necessities]

Thanks, I am new to the forum and posted in the wrong place. Thanks to everyone who have offered ideas.

 

[Bare Necessities]

Well, problem solved. I have to admit it was not what I thought it would be. I thought I was going to find a plugged line. My son brought his vacuum tester down to the boat and helped me. We attached to the fuel line at the lift pump and we could not build any vacuum going toward the racor and fuel tank. We thought we may have a crack in the line. The line goes under the gen so we disconnected the line at the racor and plugged that end. We were able to pull a vacuum and hold it. We knew that line was okay. Next we disconnected the tank side line at the racor and we could pull fuel from the tank with no problem. That leaves the problem isolated to the racor. We hooked the vacuum to one side of the racor and plugged off the other side and sure enough we could not build a vacuum. We disassembled the racor and found that the gasket between the top and bottom housing was leaking air (not the top filter gasket). Reassembled with a new gasket and all is well. Thanks to all of you that offered suggestions. I am glad to say she is running like a singer sewing machine. Thanks

 

[FF]

Many fuel problems can be easily found with a hand pump ,suction or pressure, actually built for changing hyd brake fluid.

Also a clean way to prime fuel filters on a non gravity setup.

​

Mityvac MV8000 Automotive ...
$28.72
Tool Discounter

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[Ken E.]

I have the Mityvac tool that FF mentions and I used it to find exactly the same genset problem you had, an air leak. A very good tool to carry on board.