Walbro diesel heater pump acting strangely

[foojin]

We have a Newport heater with what Dickinson calls a "heavy-duty" Walbro fuel pump (part #20-002).

It's a year-old and until recently worked fine. Now, when I turn it on, for about 30 seconds it pumps normally, then the pumping begins to pick up speed, sometimes becoming very fast, almost constant.

To get it to normalize, I must turn the pressure knob on the pump, increasing or reducing pressure, it doesn't seem to matter. When I do that, the pump returns to normal, usually right away, and then works fine until the next time I light it up.

It's hard to tell if the haywire pumping affects the fuel flow, but does not seem to.

Any ideas? My local Dickinson dealer had never heard of such a problem.

[Boatyarddog]

I think the pumps internal check valve may be not seating properly, it's a regulator as well as a pump.
Expensive little bugger.
Maybe why Dickenson had no answer.


Sent from my iPad SV Cloud Duster

[Bobby Wandering]

Hi, Did you get this problem resolved? I have a similar problem and was able to get a baffle rebuild kit from Fisheries Marine in Seattle for $5. Same exact fuel pump. Same exact problem until the pump just finally gave up the ghost.

I will be tackling this project this week after I get back to The boat from work. I will start a new thread.

Just curious.
Bobby

[foojin]

Originally Posted by Bobby Wandering

Hi, Did you get this problem resolved? I have a similar problem and was able to get a baffle rebuild kit from Fisheries Marine in Seattle for $5. Same exact fuel pump. Same exact problem until the pump just finally gave up the ghost.

Bobby, no we haven't been able to fix it. Have drained to the lines, etc, etc, but no resolution. No one I have talked to could say whether it was the pump or the lines. It's been pretty disappointing.
Looked on the Fisheries Marine website and found a "bellows replacement kit" for $5 something. Assume that's the same part. Have you been told that will solve the problem. If so, I'll drive to Seattle, maybe take in the boat show afterall

[Bobby Wandering]

Yes, I have been told this will fix the problem. The key to this diagnosis was I pinched shut the fuel outflow line and turned on the switch. The pump should fill the line to pressure and shut off. Mine kept running. It was many tries at cleaning the heater, bleeding the lines, new filter, new oil metering valve, disassemble, reassemble, repeat. The burner just kept acting like it was starved for fuel. The flames never climbed up out of the pot and burned lemon yellow.

I will begin this project tonight. It will be a new thread since I cannot find one on this subject. I have no idea what I am doing, but I am up for the challenge. $5 VS $135? No brainer, give it a try. The post will include pictures all the way through.

S/V Wandering Star
Tacoma, WA

It is what it is.

[AnchorageGuy]

If you take the Walbro apart you will find a screen inside. This screen may very well be partially blocked and allow just enough fuel to not allow the pump to shut off but not enough to run the heater. Chuck

[Bobby Wandering]

Originally Posted by AnchorageGuy

If you take the Walbro apart you will find a screen inside. This screen may very well be partially blocked and allow just enough fuel to not allow the pump to shut off but not enough to run the heater. Chuck

Thanks, Chuck. Awesome info there. There is also mention of a filter. Would you know if this is the screen? Or am I looking for an actual filter?

S/V Wandering Star
Tacoma, WA

It is what it is.

[AnchorageGuy]

Bobby, It depends on the type of pump. One has a flat screen inside and the other has a filter element insert inside the pump where the lines attach. Chuck

[AnchorageGuy]

Taking another look at the pump you have, it should have a screen when you remove the 3 screws to take it apart. be careful not to loose any pieces. Chuck

[AnchorageGuy]

Another thought. It almost sounds like the pump is loosing prime and just sucking air. Disconnect the pump from the heater but leave it connected to the fuel tank. Let it run in a bucket until only fuel come out. Reconnect and see if all is well. If it stops again later, there is an air leak somewhere. Chuck

[Bobby Wandering]

Thanks again, Chuck. Please watch for my big foray into pump rebuilding coming to a thread near you. I am finished hijacking this one.

S/V Wandering Star
Tacoma, WA

It is what it is.

[foojin]

Originally Posted by Bobby Wandering

I am finished hijacking this one.

Feel free, Bobby. I'm sitting on the edge of my seat.

[GordMay]

See pages 13 thru’ 17 ➥ http://www.dickinsonmarine.com/Manua...ual-2011-2.pdf

[Bobby Wandering]

Thanks GordMay. I have the same directions. However, my But pump is a WEP style. The part number I was able to find stamped on the pump is 2403. If you compare the pictures, the newer model has fuel running through the center. Mine has fuel entering and exiting at the top.

There is a ton of useful information in that .pdf. I know it almost by heart. I should have thought to include it in the thread. Thanks again.

S/V Wandering Star
Tacoma, WA

It is what it is.

[Bobby Wandering]

Originally Posted by Bobby Wandering

However, my But pump is a WEP style.

Aww, geez,

S/V Wandering Star
Tacoma, WA

It is what it is.