Petrol backs up when filling tank - help required please

manofthefora

I have an '06 Toyota Corolla Verso. Recently I find that when I go to get a fill of petrol, the nozzle shuts off almost immediately. I can just about get a small trickle into the tank. The tank is less than 1/4 full.
I have researched this (well known) problem and there are lots of different explanations. For a start it makes absolutely no difference where I position the nozzle nor at what angle - the most common suggestion..
There is talk of vent pipes for the tank. With the nozzle hardly in the filler, there is plenty of room for the air in the tank to escape. Yet it still shuts off. This has happened at several different filling stations.
I spoke to a Toyota service mechanic who said he never heard of the problem! I had hoped it might be something peculiar to the Verso. He did mention something about an anti-siphon gismo in the tank.
I am a bit afraid to start pushing coat hangers down the filler tube.
So, please, can anyone shed more light on this issue? Suggestions? Any Corolla Verso specialists out there?
MOTF

K.Flyer

Have you tried to fill the tank by pulling the handle only about half way and holding it there instead of full way. I had a similar problem and this was how I got around it and it didn't take long to fill the tank.

manofthefora

See OP above!!
"For a start it makes absolutely no difference where I position the nozzle nor at what angle - the most common suggestion"

CJhaughey

manofthefora wrote: »

See OP above!!
"For a start it makes absolutely no difference where I position the nozzle nor at what angle - the most common suggestion"

Read the post, They are talking about pulling the handle halfway from full flow to empty, not adjusting the angle of the nozzle.

manofthefora

OK, I understand. Yes, I have tried holding the trigger in several positions. The only way I can get petrol in is to very, very lightly hold the trigger. It dribbles in and takes forever to buy €10 worth.
I was hoping that someone who knows the construction of the tank on a Verso would shed some light on the problem.
Also I'd like to know if it's safe to go poking with wires or tubes? I don't want to damage the anti-siphon device - if there is such a thing!
MOTF

CJhaughey

Check the vent lines from the tank to the evap. filters would be my guess, if these small lines get blocked the tank can become hard to fill.
Although you think the nozzle isn't blocking the filler neck the fuel flowing down will create an airflow that will make it hard for air to rise back out.
I'd start under the car and find the fuel feed and return and see where they lead to and if they are free flowing.Lift the back seat and the fuel pump is visible under the metal cap and the feed return are in that , try blowing through them and checking they flow freely.
Also the vent pipe coming off the main filler neck is free.

manofthefora

CJhaughey wrote: »

Check the vent lines from the tank to the evap. filters would be my guess, if these small lines get blocked the tank can become hard to fill.
Although you think the nozzle isn't blocking the filler neck the fuel flowing down will create an airflow that will make it hard for air to rise back out.
I'd start under the car and find the fuel feed and return and see where they lead to and if they are free flowing.Lift the back seat and the fuel pump is visible under the metal cap and the feed return are in that , try blowing through them and checking they flow freely.
Also the vent pipe coming off the main filler neck is free.

Many thanks. That's the sort of advice I was hoping for!
Will check out your suggestions over the weekend.
MOTF

manofthefora

manofthefora wrote: »

Many thanks. That's the sort of advice I was hoping for!
Will check out your suggestions over the weekend.
MOTF

Attached is a photo of the filler cap area. There are two holes visible (apart from the filler entrance). I pushed a thin plumbing wire down both and they appear clear. I wonder why there are two holes there?
Looking under the car I can see the vent pipe and it looks good - no visible kinking or damage.
Still don't know how the whole structure hangs together on a Verso. I guess I should go get a parts/maintenance manual??
Finding it hard to believe that this is not a known problem.
MOTF

scannerd

There will be a one way value on the EVAP system which leads from the tank / fill neck to the charcoal canister - this is where most of the air from the tank will pass through as you fill (to capture the fumes), your issue could be the pipe, the one way value, or the canister, need some testing to see which it is.

have a look at this

https://www.youtube.com/watch?v=

manofthefora

manofthefora wrote: »

Many thanks. That's the sort of advice I was hoping for!
Will check out your suggestions over the weekend.
MOTF

scannerd wrote: »

There will be a one way value on the EVAP system which leads from the tank / fill neck to the charcoal canister - this is where most of the air from the tank will pass through as you fill (to capture the fumes), your issue could be the pipe, the one way value, or the canister, need some testing to see which it is.

have a look at this

https://www.youtube.com/watch?v=

HHHmmm!! I can't see a charcoal cannister under the car. There appears just to be a breather pipe (about 1cm diam) running from the top of the fuel tank, alongside the large filler pipe, back up to the filler cap area. The area around the filler cap can't be inspected. I really need a manual/parts diagram to see how this thing is put together (like, is there actually a charcoal filter on my Corolla Verso?). Do such detailed manuals exist?
MOTF

manofthefora

manofthefora wrote: »

HHHmmm!! I can't see a charcoal cannister under the car. There appears just to be a breather pipe (about 1cm diam) running from the top of the fuel tank, alongside the large filler pipe, back up to the filler cap area. The area around the filler cap can't be inspected. I really need a manual/parts diagram to see how this thing is put together (like, is there actually a charcoal filter on my Corolla Verso?). Do such detailed manuals exist?
MOTF

I dont know about your car but on mine if I take off the wheel arch liner I can see in around the filler cap

manofthefora

BrownFinger wrote: »

I dont know about your car but on mine if I take off the wheel arch liner I can see in around the filler cap

Thanks but please can you tell me how to do that? !!
The top plastic cup holder snaps off - is that what you mean?
If so, I can only see the main filler pipe.
Can't see how the breather is connected.
MOTF

mullingar

You need to check 2 things.

1. Make sure something didn't go down the pipe and got caught in the anti-siphon mesh so the fuel backs up into the filler pipe.

2. Check to see if the air escape pipe is clear.

https://toyota-europe.epcdata.ru/img_eur/A1/771394D.png

manofthefora

Move along, nothing to see here??
Lots to see!! Great diagram. Exactly what I wanted.
Can you say which part is the anti-siphon mesh? Looks like 77108B??
Many thanks.
MOTF

mullingar

manofthefora wrote: »

Move along, nothing to see here??
Lots to see!! Great diagram. Exactly what I wanted.
Can you say which part is the anti-siphon mesh? Looks like 77108B??
Many thanks.
MOTF

77108B is a non-return valve to stop petrol going back up when you go around a corner.

The anti-siphon mesh is usually built into the tank.


Plenty of cheap flexible borescopes on ebay for iphone/Android if your not handy with the tools to see if anything is in the way.


Oh, that image is for the 05+ Verso with chassis code starting with: znr11r

manofthefora

Brilliant!!
Off to beg/borrow/buy a borescope.
Thanks again
MOTF

Meeoow

Same happened my focus.
Mechanic found something in fuel tank. It was like a circular plastic flat yoke.
Took ages to fill, pump kept clicking off.
Havnt a clue how it got into tank. But once it was fished out, the tank filled no problem.

manofthefora

Thanks for that.
I have inspected the filler cap to see if some washer/seal has fallen off and down the fuel line.
But for that I need to see a Corolla Verso with a working filler cap!!!
I'll hang around a filling station till a Verso arrives!!!
MOTF

manofthefora

manofthefora wrote: »

Move along, nothing to see here??
Lots to see!! Great diagram. Exactly what I wanted.
Can you say which part is the anti-siphon mesh? Looks like77108B??
Many thanks.
MOTF

You for real mate? at the end of the line...
Leave this to a pro man, youll do more damage.
Its the air escape most likely the issue.

manofthefora

Tried camera and could see nothing.
Left the car in for a service.
They removed the filler pipe and the breather pipe from the fuel tank and could see nothing wrong.
They blew air down both pipes and there was no blockage.
Next step is to replace the filler pipe assembly - would cost E360. I declined.
Drove to a filling station and the problem had disappeared!!!
Filled tank in 2 minutes versus 15 minutes for the last few weeks,
Can't figure it.
MOTF

marriedcouple

Glad it got sorted - not mechanically minded at all but remember an old car of ours was similar. We never got to the bottom either and neither did our garage. Remember pulling in one day to a petrol station and an attendant offered to fill it. I said put in 50quid worth forgetting it was hubby's car and not mine -- poor bloke was there half the day trying to fill it. It was incredibly frustrating so I feel your pain!

CJhaughey

manofthefora wrote: »

Tried camera and could see nothing.
Left the car in for a service.
They removed the filler pipe and the breather pipe from the fuel tank and could see nothing wrong.
They blew air down both pipes and there was no blockage.
Next step is to replace the filler pipe assembly - would cost E360. I declined.
Drove to a filling station and the problem had disappeared!!!
Filled tank in 2 minutes versus 15 minutes for the last few weeks,
Can't figure it.
MOTF

THe blockage may not have been enough to stop compressed air at 100psi, but it may have been enough to stop the air from breathing as you filled.