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Onan: 2.8KVFA26100C turns over but does not start

davedavedave

Registered
Hi, This generator was attached to my Class B camper. The prior owner did not use or maintain it. So it probably had old gas in it for a very long time. It turns over but does not start, or even catch.

Model: 2.8KVFA26100C
Serial: I943237793
120V, 2.8kW, 3600RPM 60Hz, Gasoline, and used 12 house battery for starting.
(Installed on a 1995 Coachman Saratoga Class B camper based on a Dodge B3500)

The generator was mounted under the floor of the van between the bumper and rear axle. I could not service it in place due to the tow bar welded to the frame directly in front of it. So I pulled it from the van and capped the fuel line. It is now sitting on my utility trailer. For trouble shooting purposes, I have a 12V battery, a gas can, basic hand tools, and an AC/DC clamp meter/multi meter. I am reasonably handy with mechanical, electrical, and plumbing things.

I googled this and tried the basics. It does have oil. When on the van, fuel was at the level of generators fuel line. It does not appear to be drawing gas from the gas can. There is no raw fuel smell at the exhaust pipe when cranking it over. Holding stop doesn't seem to engage the fuel pump but I don't know if it should for this model.

(I hope I did this post correctly. I down sampled the images to reduce file size and included all info from the sticker.)

Cheers,

Dave

image-20200518_165855.jpg

image-20200518_165914.jpg
 

davedavedave

Registered
Alan,

Thanks for that reply. I have + voltage at the pump and continuity to ground. To test flow I dropped the suction side fuel line in a gas can and routed the pressure side back to the gas can to observe flow. I cranked for while and saw no flow. To test further I supplied +voltage directly to the pump. It made sounds like an impact wrench and no fuel was pumped. When I checked the fuel filter - there wasn't one! It was replaced by a straight pipe.

Assuming a good pump should be able to draw fuel from a line placed in a gas can - the pump is bad.

Does this shopping list look correct for further work?

fuel pump 405-5827-02 Spec F-K
fuel filter kit 149-2137
air filter 140-2105 (why not)
spark plug 167-0263-02 (why not)
fuel line (I have some already)
oil (I have this already)

-Dave
 

davedavedave

Registered
You are spec C, and you're reading the wrong column on the fuel pump page - your fuel pump should be 149-2588, The rest of your list looks fine.

Alan
I'm having trouble finding an exact match for pump 149-2588. I did find these
https://www.searspartsdirect.com/product/56xbw13bsk-0071-739/id-149-2588 (best bet?)
https://powerparts.ecrater.com/p/18154593/onan-149-2332-00-2588-fuel-pump
https://www.summitracing.com/parts/atx-e11009

Nothingbutdarts link was a to a list of pumps with a range of specs. It wasn't clear which one to get. I would like a close match in both form and spec so that it will install easily and perform as expected.

Cheers,

Dave
 

Pauls12

Subscriber
Age
76
Last Subscription Date
12/07/2019
Darts said # 40178 was the right pump for your generator???
 
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len k

Subscriber
Last Subscription Date
12/12/2018
Gas pump on my Onan 7NHM gen didn't work when I got it. Gen had sat for few years before I bought it.

Pump on mine looks like pump your gen originally came with ( see your parts manual paper page 22)


My pump was a solenoid type, normally would go click , click, click, click......... But it did not.
I figured it was stuck and having nothing to lose I took it off , held it in my hand, and give it SHARP rap with a small LIGHT steel hammer in both directions of all 3-axies ( x,y,z) . I took care NOT to dent it.

I plugged it in and it ran, click, click, click,
I added gas hose and some brown crud flakes flowed out
Apparently ethanol crud dried up and glued diaphragm in place.
Works great now.
 
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davedavedave

Registered
I connected the pump direct to 12V+ and it does make a solenoid pumping sound but moves no fuel. I rapped on it with wrench while it was on and no fuel moved.
https://photos.app.goo.gl/hhtxc8fbH1MpCf3B7
Short video of the pump while direct connected to 12V+. The pressure side was directed to a catch can. Suction side fuel line was dunked in a gas can. Since no fuel moved I ordered the pump and other parts from Sears parts direct because they have easy returns.

Thanks for all the support. I'll keep you posted.
 

len k

Subscriber
Last Subscription Date
12/12/2018
Your pump looks just like mine.

Since you have nothing to lose , try blowing compressed air thru pump in direction gas normally would flow. Possible some debris is keeping one of the 2 internal check valves open.

I'ld start with low presure ~10-20 psi then try it, if doesn't pump repeat with higher and higher pressures.

I have 150 psi in my air compressor tank, I think that would create a huricane inside pump that would blow any crud out
 
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