Is there an inline fuel filter besides the Onan filter

[klutchdust]

2015 Forest River work and play. It has a fuel station and an Onan mounted on the nose. Yesterday it was running fine then quit, it has 25hrs on generator, previous owner used it very little.
So i checked the filter behind the fuel pump and it was clear, the pump ran constantly and was not picking up fuel. i used a small hose into a fuel can to eliminate the long fuel line from the rear of the trailer and still nothing.
This morning it started and i ran it 3 hours underload. Since I had the unit, about 6 weeks now I have put 10 hrs on generator.

My thoughts are a clogged fuel filter someplace else. electric fuel pumps don't repair themselves overnite. With the fuel station and pump nozzle on the rear, is there another fuel filter somewhere?
Reminds me of the urban legends about a plastic bag in the fuel tank sucking up to the line and clogging it....

[dedmiston]

klutchdust wrote:
Well its running fine now. Hoping to get some trout fishing in next week in Bishop,ca.

Good job.

Fishing in Bishop sounds perfect. Enjoy.

[klutchdust]

dedmiston wrote:

klutchdust wrote:

Dirtclods wrote:
I's lean towards old fuel made it's way into the carb and gummed some things up.

When I removed the line going to the carb and turned on the pump nothing happened. I inserted a small line from the fuel filter into a can of gasoline nothing happened.
I replaced both. I dismantled both the filter and the pump looking for reasons why it may have bin gummed up or whatever and saw nothing.

The 12 volt fuel pump is interesting inside, a cylinder that hammers back and forth drawing fuel. It all looked good. My guess is the seals/rubber inside the pump didn't allow vacuum to happen. but then again....like the little woman says to me....what do you know :B

:B :B :B

Yeah. Whadda you know, man?



:B :B :B

Well its running fine now. Hoping to get some trout fishing in next week in Bishop,ca.

[dedmiston]

klutchdust wrote:

Dirtclods wrote:
I's lean towards old fuel made it's way into the carb and gummed some things up.

When I removed the line going to the carb and turned on the pump nothing happened. I inserted a small line from the fuel filter into a can of gasoline nothing happened.
I replaced both. I dismantled both the filter and the pump looking for reasons why it may have bin gummed up or whatever and saw nothing.

The 12 volt fuel pump is interesting inside, a cylinder that hammers back and forth drawing fuel. It all looked good. My guess is the seals/rubber inside the pump didn't allow vacuum to happen. but then again....like the little woman says to me....what do you know :B

:B :B :B

Yeah. Whadda you know, man?

:B :B :B

[klutchdust]

Dirtclods wrote:
I's lean towards old fuel made it's way into the carb and gummed some things up.

When I removed the line going to the carb and turned on the pump nothing happened. I inserted a small line from the fuel filter into a can of gasoline nothing happened.
I replaced both. I dismantled both the filter and the pump looking for reasons why it may have bin gummed up or whatever and saw nothing.

The 12 volt fuel pump is interesting inside, a cylinder that hammers back and forth drawing fuel. It all looked good. My guess is the seals/rubber inside the pump didn't allow vacuum to happen. but then again....like the little woman says to me....what do you know :B

[Dirtclods]

I's lean towards old fuel made it's way into the carb and gummed some things up.

[rockylarson]

dedmiston wrote:
And to address your question about the fuel filter, I think Onan deleted the fuel filters at some point because they caused more problems than they solved. Does this ring a bell to anyone?

I believe the pre-carburetor fuel filter was eliminated or as in my case replaced with a flow thru fitting. The pre-pump fuel filter was still available the last time I looked and I just replaced mine this week.

[enblethen]

I wonder if the battery could have leads reversed? Pumps would run backwards.

[wopachop]

klutchdust wrote:
So i checked the filter behind the fuel pump and it was clear,

My fuel filter is also right before the fuel pump. But its made out of metal. Is yours a QG 5500 evap?

I wonder if the previous owner also had an issue with the generator stopping. Replaced the stock filter with a clear filter from the auto parts store.

[wopachop]

klutchdust wrote:

So....my thoughts about the pump, why would the pump run continuously and not pick up fuel either from the supply line or a fuel container I had nearby.
next day I prime it, it runs 5 seconds off the main fuel line which is at least 25 feet starts and runs fine.

I have the same thoughts. Happens to both the generator fuel pump and also the fresh water pump.

Both are self priming i believe. But i think with just air in there the suction can be too little to pull water or gas into the pump. One answer to your question could be a cracked fuel line sucking air. You wait a couple days and the gasoline soaked crack might actually become soft and somewhat seal itself. So the fuel pump now miraculously works. The problem is still there but just hiding for a bit.

But you ran a small fuel line and the pump still didnt prime. Which means there is still a suction problem.

If i was there i would pull the fuel line directly off the carb and then either suck with my mouth if an emergency, or use a mighty vac or syphon pump to pull gas through.

Really dont think its a fuel pump problem. Ideally youre supposed to run the genny for 1 hour every month under a load. You might be experiencing parts that sat for awhile, developed some film and that sludge that ethanol gas turns to, and is now working itself through.

Whats up with the fuel filter? Youre seeing a small clear fuel filter? That might be a secondary filter the previous owner installed. I think the stock onan filter is a metal canister.

[klutchdust]

schlep1967 wrote:

klutchdust wrote:

The trailer is not far off from being level, it's in my backyard.

It will cost you nothing to level the trailer.
What is "not far off"? When dealing with liquid spread out over an oil pan maybe 12" x 12" not far off can make a difference. If it is 1 inch off over the 8 feet it will be 1/8" difference from one side to the other on a 12" oil pan. Are there any blinking lights on the generator panel when you try to start it? 2 blinks indicate low oil on many Onans.

The trailer isn't sitting on the level pads i had for my class c and the next time the trailer is out I plan on putting concrete pads for the tires to sit on. It's pretty dang level and before this incident it ran fine after many uses.

So....my thoughts about the pump, why would the pump run continuously and not pick up fuel either from the supply line or a fuel container I had nearby.
next day I prime it, it runs 5 seconds off the main fuel line which is at least 25 feet starts and runs fine.

Low oil pressure would not allow the pump to run and not pick up fuel, the pump isn't that complex, it either pumps or it doesn't, comes on or it doesn't. so this pump ran but did not pick up fuel..hhmm...

[schlep1967]

klutchdust wrote:

The trailer is not far off from being level, it's in my backyard.

It will cost you nothing to level the trailer.
What is "not far off"? When dealing with liquid spread out over an oil pan maybe 12" x 12" not far off can make a difference. If it is 1 inch off over the 8 feet it will be 1/8" difference from one side to the other on a 12" oil pan. Are there any blinking lights on the generator panel when you try to start it? 2 blinks indicate low oil on many Onans.

[wopachop]

klutchdust wrote:
This morning it started and i ran it 3 hours underload.

So it ran for 3 hours. Has it failed since then?

A temporary water bottle gas tank comes in handy for troubleshooting small engines. If you make one for your generator just stick the original fuel line into a gas can. You can watch the fuel come out to help determine if the pump is weak or the filter is clogged.

I think you just had air in the fuel line. Or the carb had some sludge that is making its way through the ports.

[klutchdust]

dedmiston wrote:
Could it be a venting problem? Try cracking your gas cap while it runs under a load.

I will try that if it quits today. it's been over 100 here this week.

[dedmiston]

And to address your question about the fuel filter, I think Onan deleted the fuel filters at some point because they caused more problems than they solved. Does this ring a bell to anyone?