I'm sure this has been asked and explained 100 times but I can't seem to find an answer for my problem.I've got an 86 Minnie Winnie with a Onan Emerald I Genset. Rv was recently purchased and I've had the generator running and seemed to be perfect. The fuel level may have gotten too low to run the generator but I've since filled it up. I've had the fuel pump out and checked it on a good battery and it ran like it should then. When I take fuel line off of pump and try to start it no fuel is coming out, I'm gonna get a meter and check to see if I'm getting power to the pump but if I'm not then where would my problem lie? Also should fuel run out of the line to the generator? I don't have any coming out so I tried to trace the line, it seems to run to the carb? Is that correct? I figured it would go to tank but doesn't seem to. Thanks for any help In advance

Well Adam, It's like this, the pump works? You tested it and it pumps fuel, but when you put it back in place, it does not pump fuel. - Right? Yes, you should have a meter, everybody should, but you should not need it here as you should be able to feel the pump when you (or a friend) holds the start button. Better yet (read the manual and check me on this) hold the stop button. This engages the "Prime" feature and the fuel pump should run. If you can feel the pump run and no fuel comes out, then there is a problem with the fuel lines to the tank. As an old coach owner, this is no surprise. I would tell you that the entire problem is caused by the EPA mandated alcohol content of the stuff that is sold as motor fuel, but that might political so I won't. The fact is that the rubber fuel lines may well have aged out. Matt

Rv wasn't at home so I bought the cheapest analog meter I could find and I'm showin 35 volts to the pump? Is this any way right??

It is looking like a fuel line problem. I do agree about these fuels nowadays! I put an ethanol treatment in everything I own that's carbureted but this one is a new purchase. So if I do have a line problem does anyone know if this line does go to the vehicle carburetor or to the tank? From what I could see it looked like it went to the carburetor

When I needed to give my generator a shot of carb cleaner I didn't want to dilute it with all the gas in the tank. I put gas in a gallon can then added the cleaner. Ran a hose from the can to the intake of the pump. It sounds like your problem may be a bad hose, cracked, making the pump suck air instead of fuel. If you try this application and the genny runs, that would pretty much show the problem is from the tank to the pump... Just a thought.... Good luck..

If there is a fuel filter anywhere in the line, it should be replaced.

Generator issue | Good Sam Community

LittleBill
Explorer
Sep 06, 2014
the HF meters work just fine, they are within .5 of a volt of my fluke
Jerrybo66
Explorer
Sep 06, 2014
LittleBill wrote:
the HF meters work just fine, they are within .5 of a volt of my fluke

I totally agree but what are the odds that all HF meters are good compared to Flukes. My Fluke was around $200.00 and HF are given away free. How much quality control was involved between the two? Maybe out of the tens of thousands of HF meters, you got lucky with one that works. Congratulations. I'm not here to argue a American/chinese tool debate, I'm just trying to find a reason for his unreasonable voltage readings. His problem is the main topic here..
BTW, for a guy who knows quality equipment, what the heck are you doing with a free Chinese meter?? They're not heavy enough to be used as a boat anchor.. :B
opnspaces
Navigator II
Sep 06, 2014
Adamgre wrote:
Ok here's what I got. When trying to start I'm showing 20v to the fuel pump. If I take a hose and put in a can of gas it still doesn't pump anything, also if I suck on fuel line to pump gas flows freely. Why would I have 20v to the pump and why wouldn't pump still work

You probably don't have 20v to the pump. As suggested put the meter across the battery and see what the voltage reading is.

If you get 12v at the battery and still get 20 at the pump then you have a second battery with 2 dead cells somewhere that is wired in series with the first battery making 20 volts.
westend
Explorer
Sep 06, 2014
He is using an analog meter, maybe reading off the wrong scale?

My suggestion would be to buy a half-way decent digital meter and see what voltage you have at the pump when depressing the prime button. With adequate voltage the pump should sound about the same as when you powered it straight from the battery. If it is about the same and you have no fuel from the line, there is probably a bad fuel line to the pump from the source. If it doesn't sound the same, you may have a bad electrical connection to the pump.

Good luck, I hope it's an easy fix.
Adamgre
Explorer
Sep 06, 2014
I did check across battery and showed 12.5 volts when sitting and same when starting generator. I tried the prime feature but I guess mine doesn't do this because nothing happened. I'm assuming the fuel pump is ran by the generator so would that mean a bad regulator?
4x4van
Explorer III
Sep 06, 2014
An '86 motorhome won't have the prime feature on the gen start switch. I changed out a failed fuel pump on my Onan 4.0 generator a few years back ('88 model MH) and added a toggle switch to prime it. BTW, I just used an automotive low-pressure fuel pump; much cheaper than an Onan unit. While running, the generator should trigger a relay that will provide 12v to the pump.

The 20v concerns me; that shouldn't be possible from a battery bank that's providing 12v.

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