Gas tank filling problem - venting issue???

Hi guys,

I have a problem others may have experienced already so I'll throw this out in case someone can shed some light.

My '94 Newmar Kountry Star has an issue when filling with gas - if you put the nozzle in the tank neck, it 'foams up' even when filling at a snails pace and clicks off the nozzle incessantly.  I've found if I use a long skinny funnel, I can fill by squirting into the funnel, but even then I cannot get the nozzle to the first 'click' or it will burp fuel out of the neck onto the ground.

It takes me about 45 minutes to get 70 gallons in this way.

The fill line is about 1.5" dia. and takes a few twists and turns on it's way to the tank.  The vent line is about 3/4 or 7/8" and doesn't seem to have any kinks in it and no glaring obvious sags that would fill with liquid fuel, but it is awfully flat pitch so I can't be sure.

In looking at the layout, the tank is hoisted pretty high between the frame rails, and the elevation of the tank neck probably isn't much higher than the top of the tank itself.

Has anyone run into this and what resolved it?  I can't picture anything getting into the system that would be big enough to plug either line.

An additional fuel problem this RV has is in starting cold - if you turn the key and continue to crank, it will not fire, if you do a cycle of about  three "crank for 2 sec, let go of key, wait 5 sec, crank for 2...." on about the 3rd or 4th try it will fire off and run like a charm.  It almost acts like it is fuel starved unless you cycle it as I described.  460 Ford engine.  Filter is new and it has plenty of pulling power so I don't suspect anything is wrong with the fuel pressure while running.  I don't suspect these are related problems, but you never know......

There are several factors.. Many motor home owners have found the vent tube (This is a small tube that lies next to the filler and "T"'s in near the top) has been kinked or has a dip in it that is full of gasoline and not venting properly.  A slight adjustment, perhaps shorteing a bit and it works.  page 2

On most motor homes the filler tube lies almost flat, there is next to no grade for the gas to flow down.... dropping the filler side jack and tilting the rig slightly to the other side may help  NOTE: If the gas station lot is ashphalt.. I recommend against this as you don't wish to "Leave an impression"

Finally.. some tanks have dual fillers.. Open both sides.  But do this carefully and NOT in California

[quote author=John From Detroit]Finally.. some tanks have dual fillers.. Open both sides.  But do this carefully and NOT in California[/quote]

Not a smart thing to do IMO; It's too easy to be pumping fuel in one side and having it running out the other side.

I have used both fillers at once, but learned early on to close one of them before the tank is filled or you'll have a mess on the side that shuts off first.  Unless you know exactly how much fuel you're tank is going to take and cap one side before getting close to full, I wouldn't recommend using both fillers at the same time.

John From Detroit said:

On most motor homes the filler tube lies almost flat, there is next to no grade for the gas to flow down.... dropping the filler side jack and tilting the rig slightly to the other side may help  NOTE: If the gas station lot is ashphalt.. I recommend against this as you don't wish to "Leave an impression"

Click to expand...

So it sounds like I am not alone in this?  I find it ironic that the largest fuel tank I own also has to be filled the slowest.

Most gas stations have concrete aprons under the canopy - dropping down the jacks and lifting the fill side is a great idea if it helps!

I've considered removing the vent tube from the connection at the filler neck, and fastening it up higher in the wheel well (using a permanent plug at the fill neck and a removeable one in the vent tube ).  I assume as flat as the fill pipe is that gas easily flows into the vent tube and can collect in any sag.

Well, as I said I've had the best luck just tilting the rig.. I discovered this by noticing that at some pumps it fills quickly

So I noted the attitude of the rig (nose down and non-fill side down seem to work best) and using my hydraulics to duplicate that.

NOTE: the attitude for your rig may be different than mine.