Technical Gas Filling Problem

I built my car with a Cobra kit car flip up filler cap in the quarter panel. Today, I drove up to fill up the tank for the first time and the nozzle shut off clicks off immediately. I really don't know how the system works. I used a handmade gas tank that was made for an old pickup truck along with the filler neck that was on the truck. There is a vent tube that runs beside the filler tube that joins the filler tube near the top. Any fix it ideas out there?

 

What’s inside the flip up gas cap?
I have a flip up gas cap and below it is a stock filler neck from a ford with the little trap door on it. The gas pump nozzle doesn’t reach far enough to push open that little door.
I can fill it if I trickle the gas in. One day I’ll take it apart and remove that little door.

 

If it's a pump nozzle like we have here with the rubber boot on it, you have to collapse the boot and create a good seal between the nozzle and filler tube which prevents fuel vapor from escaping. Must be a pressure sensor in the pumping system. I can't imagine you don't know this unless you live somewhere they don't have this. Did you try another pump?

 

Like mention above,
Pics of inside of fill cap & elbow angle ,
size of vet tube
In Va & south not too many fuel pumps with the vapor boot

 

This.^^^

The pump will normally shut off when the tank gets full and the end of the nozzle gets immersed in fuel.
If the nozzle is not pushing the little flap open, as soon as you pull the trigger, the trapped fuel in the upper filler neck will shut the pump off.

It is a good idea to leave the working "roll-over valve" in there. You may need to take a section out of the filler neck above the valve so the pump nozzles can reach it properly.

 

The vent tube on the filler neck needs to be plumbed back to the top of the tank and not capped off. The old truck filler neck probably doesn't have the roll over flapper valve.

 

Also if there is a bend below the fill hole it will shut off also. Any back pressure will shut it off. I finally found the sweet spot angle on my Austin and now all is good.

 

He already said he has the vent tube set up.......

 

Yep, sometimes it can be that simple. If the bend causes some splash-back of the fuel towards the nozzle it will shut the pump off. I also had one that would only fill if you held the nozzle and your mouth just right.

 

That is exactly how mine works. LOL

 

I also have a really old TV that only gets reception if I stand on my head in the corner, with the same stupid look on my face........

 

Now we're really getting somewhere.

 

3 hail marys and salt over the shoulder always works.....he he he

 

I had the opposite problem.

Filling up the other week, wondering why it hadn't clicked off, only to see £20 of fuel pouring onto the floor from the filler/tank joint!

Left a nice trail of melted asphalt back to my house haha

 

I found this out when I drove my vintage but non-HAMB vehicle to Cali from Michigan a while back.
His question is a good example of why everyone needs a location listed along with their user name. If he is in a state without that type of nozzle, you wasted your time replying.

 

And if he is in another country altogether, it really was irrelevant info. I think the OP is Canadian.

 

Try some different angels on the nozzle if you not allready have done that.
Every car i have its own angle to work

 

In the car business you need to know all the angles.

 

Attach some hose to a funnel, gets you far enough in to work. Had to do it to a 64 Buick with the filler under the license plate.

 

As the gas goes in the air has to come out. Just need to figure out what is stopping the air from coming out.

 

A long neck funnel can solve a lot of problems.

 

He is and we don't have the boots on our pumps where he is.

 

What you are describing is not uncommon. I've experienced it with my daughter's 2001 Chevy S10 and my 2017 Ram 1500. At one station, the nozzle got stuck in my Ram. Rather than risking damage to my truck by trying to remove the nozzle, I called the station attendant to do it, thinking the station would be responsible for any damage. Fortunately, he was able to remove it without doing any damage. You might find a local station that is more pump-friendly, as far as your truck is concerned. Of course, that won't be any help on trips.

I would also avoid setting the pump and leaving your vehicle unattended because it might not shut off when the tank is full.

 

I found a kink in the rubber vent tube so I shortened it to take out the kink, went back to the gas station and still not working. Oh the joys of the first days on the road.

 

I had an OT 84 Ford F150 that would do that in hot weather. Fill up the fill hose and shut off, let it run down, repeat. Had to pump slow. Would take 30 minutes to fill up. Never in cool or cold weather, always 80* or above. Never could get it to stop. Checked vent, fill hose, etc. Was reading one day and ran across an article talking about the Reid vapor point of gasoline. Seems warm weather gas is formulated differently than cooler weather gas. Had to watch where I bought gas, some small stations were worse than the big chains. Figure they bought whatever was in the tanks at the refinery while the big guys had a certain formula that they went by.

 

Just about to post same thing. seasonal blends differ. And i don't know this for fact but have been told that pump manufacturers make the handle so they will cut off faster due to overfilling and running on the ground.

 

I think the sensitivity of the automatic shut-off was modified to prevent overfilling and flooding the 'fumes canister' portion of emissions systems, thereby reducing the effectiveness of the systems. Part of the California CARB laws......

 

Pouring gas in with a gas can and listening can reveal some good information.

Can you post some pictures of what you have for a tank and fill? I have a 79 C30 dump truck with a home made fill. I found out with several modifications that the 1.5" fill hose and the .75" vent hose only need to be slightly sloped toward the tank to work properly.

 

I know it’s a ot vehicle but my 2007 Ford F-150 you must hang your tongue out the left side of your mouth while having to pee really bad with the nozzle barely in the gas fill 1” to put gas in it. The only vehicle I have ever had where it was almost impossible to put fuel in it. Until I figured that out I had to use a large long funnel.

 

That would be about 1/2 cup at today's prices!