Lots of Problems

[McFalls2014]

We bought our first toyhauler 2 weeks ago. It had sat a while before we bought it and it has been a process getting everything in running order. It has an Onan 4000 generator on it along with the fuel tank and pumping station. Here’s where we’re at.....
There’s a tube hanging from the top of the fuel tank. Vent hose? Nevertheless it’s dripping fuel. Not pouring but its enough to make a noticeably big dead spot in my grass. The tank is building pressure so much that when I unscrew the fuel cap it actually pushed fuel back out. Pump station isn’t working at all. The motor runs but no fuel comes out. The generator will run for approx 30-45 minutes then shut down like it’s starving for fuel. I feel like all of this is linked to one issue but don’t know what it is. Help Please!!

[McFalls2014]

fj12ryder wrote:
You might check to make sure your pump is wired correctly. They will run backward if wired wrong, no fuel, and will pressurize the tank. Perhaps the PO tried to fix a problem and put it back together incorrectly. Just a thought.

That didnt even cross my mind! Will check it this evening. Thx!

[fj12ryder]

You might check to make sure your pump is wired correctly. They will run backward if wired wrong, no fuel, and will pressurize the tank. Perhaps the PO tried to fix a problem and put it back together incorrectly. Just a thought.

[McFalls2014]

Weve been attempting to troubleshoot this situation. Dropped the tank this weekend and found that the hose just hanging from the top of the tank was connected to a rollover safety vent valve. The valve looks all gummed up and seems to be stuck. Still makes very little sense to me. That would explain the drip of fuel if the pressure is forcing fuel through it but seems that if it was stuck open it would be constantly venting and there would be no pressure. All other lines, valves, etc look good. Nevertheless I ordered a new valve. We will see if that fixes the issue......

[wa8yxm]

dedmiston wrote:
Try cracking your gas cap and run it again. If it's not venting properly, maybe it's starving the gen for fuel.

Is it hot where you are? Maybe the tank is so full that its burping fuel out of that lower vent line as the fuel expands.

How many hoses on the tank? If only the one than crack the cap to run generator. If two one may be a vent but you will need someone on hand to eyeball it.

True story: A few years ago I worked the "Haunted Trail" My station needed power and a Honda EU-2000i was the source.> Well it ran for a couple minutes and died, Ran for a couple and died The park folks were busy not going to the barber (Tearing their hair out) when I fixed it for them.. Without touching it.

"Did you open the fuel tank vent valve in the cap?"

A very red faced park "Technican" then opened the vent and it ran for hours.

[dedmiston]

McFalls2014 wrote:

Hey McFalls - There's a little more to it than that.

To post an image, you need to host it somewhere publicly first.

The quickest/easiest way is to drag it to this page first: http://photoposting.is-great.net/?i=1. The page will generate a code. Copy that code and then paste it here.

If it's a HUGE image, then enter "width=800" (or smaller) before the closing IMG tag.

[ajriding]

Possible that the hose off the top of the gas cap is meant to pull gas out of an auxualliry tank. How big is your gas tank on the gen?
On little generators that have fuel pumps and 1 gallon tanks it is common to use a 2nd tank. The hose connects them. As the gen burns fuel it sucks gas out of the generator tank and at the same time sucks gas out of the connected aux tank. When the aux tank is empty it just sucks air out of the aux tank then starts to use up all the fuel in the generator's tank.This method gives the user of a little generator a lot longer run time between fillups.
If this is what your hose was for then just remove it, or get a new gas cap as that one might have been altered and damaged so cant go back to new.

Also, if gen has sat, then critters maybe made a nest inside the case. No pics, so not sure, but high-end gens like Onan are enclosed in a box, and the air is forced over the cyclinder head and that cools it. If there is a critter nest on the cylinder head then your motor is over-heating and shutting down as a fail-safe.
Take the cover off the generator and have a look.
You need good air flow.

[McFalls2014]

[McFalls2014]

dedmiston wrote:

McFalls2014 wrote:

dedmiston wrote:
Try cracking your gas cap and run it again. If it's not venting properly, maybe it's starving the gen for fuel.

Is it hot where you are? Maybe the tank is so full that its burping fuel out of that lower vent line as the fuel expands.

Its not hot, in the low 70s. Tried cracking the cap yesterday and it ran a little longer than normal but still shut down. What has me really confused is what is the line running from the top of the tank dripping fuel? If thats the vent line it should be venting with or without a vented cap I would think. Correct me if Im wrong as we are new to all of this. If it was clogged how would it drip fuel?

It's possible that it isn't clogged, but just poorly designed. Maybe it's too small to vent enough, but large enough to puke out some gas. Those actions also work in the opposite direction of each other, so maybe a spider web is allowing gas to drip out, but won't let air in?

What brand is your hauler and how long did it sit? And how many hours are on the gen? This will tell you how much the previous owner used it and whether he used it enough to service it or not.

Also, I just re-read your original post and now I'm not sure if I'm picturing your setup correctly or not. Do you have separate tanks for your gen and fuel station? Or do they share a tank?

Brand: We love our hauler, but the manufacturer didn't have much experience with toy haulers and a lot of the systems were designed poorly. Luckily our gen has never been a problem, but the fuel station doesn't vent well and it will suck itself inside out if I don't crack the gas cap before I pump fuel into our buggy. I only bring this up because there's a difference between "broke" and "designed by morons". You need to figure out which category you're in before you can fix it.

Sitting Around: If your hauler has been sitting around for a long time with gas in the tank(s), then that could explain the rough running. You don't know yet whether the gen is getting starved for fuel or if there's something else wrong with the gen. Maintaining the gen is pretty easy, so I would start by performing all the basics: change the oil & filter, plugs, air filter, and inspect the fuel filter (if it has one). Those fuel filters are known to be trouble and they're cheap enough to just replace it even if it isn't part of the problem.

Next I would deal with the fuel. It's not like a bike where you can just drain the tank into a 2 liter Coke bottle, but you can siphon the old gas into a couple of jugs while you troubleshoot this. I would siphon out as much of the old gas as possible, pour in a bottle of Seafoam and new gas, run it long enough to let the Seafoam get into the carb, and then let it sit for a day or more to let the Seafoam do its thing and then test it again. With fresh fuel, new oil & filter, new plugs, new fuel filter, and new air filter, it will hopefully be happy again and run like normal.

If it sat for too long without being exercised by the previous owner, then there's a good chance the carb is varnished. People will tell you that they service their own carbs, and Onan will tell you they can't be serviced. Who knows. They aren't very expensive to replace though.

About the pumping station...

There's a notorious problem with the gears in the pump handle. I can't say if this is your problem or not, but post in the Toy Hauler Forum here and we can work with you on that. Basically, there's a plastic gear in the pump that swells up. I think it's about the diameter of a quarter and the thickness of two or three quarters. When it dries out (like after sitting unused for a long period of time), it swells up in thickness. The fix for this is to either replace the gear or remove it and sand it down 1MM at a time until it works.

The gear problem is a weird one and it's been an issue for more than 15 years that I can remember. The weirdness is that some people have the issue and it's like herpes and never goes away. Those people have to keep a baggie of spare gears and replace them every year or so when they go bad. I didn't use the fuel station on my last hauler much and didn't mind when it stopped working. I use the pump all the time on our current hauler and it's never given me any trouble (except that I have to crack the gas cap every time I use it).

Sorry that none of this is any kind of magic bullet answer, but I bet we'll get you fixed up.

And either way, drop by the Toy Hauler forum and introduce yourself. Add your hauler info (and the toys, if you feel like it) into your profile so folks will know your setup better.

Take care.

Thanks, I updated my profile with more info. Im not much worried about the pumpstation at this time but would like to figure our the generator and pressure issue. We have dont all the above on the generator and have added Seafoam and fresh fuel. We actually mixed some Seafoam and fuel in a jug and let the gen pump straight from it and it ran forever so Im confident the problem is fuel related. I purchased a vented fuel cap today on my lunch break and am interested to see if it makes a difference. The hose out of the top of the tank is still a mystery.

[McFalls2014]

dedmiston wrote:
Also, how large is the fuel vent line that's leaking? What diameter and what length?

Currently not with the hauler but diameter, approx the size of a pencil and what I can see of it is about 8-10 inches long.

[dedmiston]

Also, how large is the fuel vent line that's leaking? What diameter and what length?

[dedmiston]

McFalls2014 wrote:

dedmiston wrote:
Try cracking your gas cap and run it again. If it's not venting properly, maybe it's starving the gen for fuel.

Is it hot where you are? Maybe the tank is so full that its burping fuel out of that lower vent line as the fuel expands.

Its not hot, in the low 70s. Tried cracking the cap yesterday and it ran a little longer than normal but still shut down. What has me really confused is what is the line running from the top of the tank dripping fuel? If thats the vent line it should be venting with or without a vented cap I would think. Correct me if Im wrong as we are new to all of this. If it was clogged how would it drip fuel?

It's possible that it isn't clogged, but just poorly designed. Maybe it's too small to vent enough, but large enough to puke out some gas. Those actions also work in the opposite direction of each other, so maybe a spider web is allowing gas to drip out, but won't let air in?

What brand is your hauler and how long did it sit? And how many hours are on the gen? This will tell you how much the previous owner used it and whether he used it enough to service it or not.

Also, I just re-read your original post and now I'm not sure if I'm picturing your setup correctly or not. Do you have separate tanks for your gen and fuel station? Or do they share a tank?

Brand: We love our hauler, but the manufacturer didn't have much experience with toy haulers and a lot of the systems were designed poorly. Luckily our gen has never been a problem, but the fuel station doesn't vent well and it will suck itself inside out if I don't crack the gas cap before I pump fuel into our buggy. I only bring this up because there's a difference between "broke" and "designed by morons". You need to figure out which category you're in before you can fix it.

Sitting Around: If your hauler has been sitting around for a long time with gas in the tank(s), then that could explain the rough running. You don't know yet whether the gen is getting starved for fuel or if there's something else wrong with the gen. Maintaining the gen is pretty easy, so I would start by performing all the basics: change the oil & filter, plugs, air filter, and inspect the fuel filter (if it has one). Those fuel filters are known to be trouble and they're cheap enough to just replace it even if it isn't part of the problem.

Next I would deal with the fuel. It's not like a bike where you can just drain the tank into a 2 liter Coke bottle, but you can siphon the old gas into a couple of jugs while you troubleshoot this. I would siphon out as much of the old gas as possible, pour in a bottle of Seafoam and new gas, run it long enough to let the Seafoam get into the carb, and then let it sit for a day or more to let the Seafoam do its thing and then test it again. With fresh fuel, new oil & filter, new plugs, new fuel filter, and new air filter, it will hopefully be happy again and run like normal.

If it sat for too long without being exercised by the previous owner, then there's a good chance the carb is varnished. People will tell you that they service their own carbs, and Onan will tell you they can't be serviced. Who knows. They aren't very expensive to replace though.

About the pumping station...

There's a notorious problem with the gears in the pump handle. I can't say if this is your problem or not, but post in the Toy Hauler Forum here and we can work with you on that. Basically, there's a plastic gear in the pump that swells up. I think it's about the diameter of a quarter and the thickness of two or three quarters. When it dries out (like after sitting unused for a long period of time), it swells up in thickness. The fix for this is to either replace the gear or remove it and sand it down 1MM at a time until it works.

The gear problem is a weird one and it's been an issue for more than 15 years that I can remember. The weirdness is that some people have the issue and it's like herpes and never goes away. Those people have to keep a baggie of spare gears and replace them every year or so when they go bad. I didn't use the fuel station on my last hauler much and didn't mind when it stopped working. I use the pump all the time on our current hauler and it's never given me any trouble (except that I have to crack the gas cap every time I use it).

Sorry that none of this is any kind of magic bullet answer, but I bet we'll get you fixed up.

And either way, drop by the Toy Hauler forum and introduce yourself. Add your hauler info (and the toys, if you feel like it) into your profile so folks will know your setup better.

Take care.

[valhalla360]

Sounds like a vent problem.
- When it gets hot, the tank pressurizes and if full can push fuel out when you crack the gas cap.
- When running the generator, at first the tank is pressurized but as the generator pulls fuel, the pressure comes down. But eventually, it gets goes negative and resists fuel being pulled out to the generator.

As mentioned, try cracking the gas cap and test the generator. It's not a permanent solution but at least it gives you a clue what's happening.

[schlep1967]

A vent hose out of the top of the tank can not push fuel out unless the tank is filled to capacity and the fuel expands. If the generator is running there is no way the tank is over full.
I'm thinking that hose is not a vent. And that the connection inside the tank goes to the bottom of the tank. That line may have something to do with your fuel station issues. For now I would plug it so gas stops leaking out.

[McFalls2014]

dedmiston wrote:
Try cracking your gas cap and run it again. If it's not venting properly, maybe it's starving the gen for fuel.

Is it hot where you are? Maybe the tank is so full that its burping fuel out of that lower vent line as the fuel expands.

Its not hot, in the low 70s. Tried cracking the cap yesterday and it ran a little longer than normal but still shut down. What has me really confused is what is the line running from the top of the tank dripping fuel? If thats the vent line it should be venting with or without a vented cap I would think. Correct me if Im wrong as we are new to all of this. If it was clogged how would it drip fuel?