[lancer_rit]

Originally Posted by 1self

The charcoal canister is there to prevent petrol fumes escaping from the filling port. It absorbs the fumes & releases the same on demand from the engine, via a valve or two, depending on the manufacturer. Repeated overfilling of petrol after the fuel dispenser cuts-off leads to the charcoal being contaminated by petrol. The charcoal power granules contaminate the tubing only meant for liquid & fumes.
...

Thanks 1self - that was a very clear explanation. Noted for my net trip to A.S.S. (unfortunately, I just got my last service done a month back)! Will post about results when I am able to get it done and experience the results ...

[condor]

Originally Posted by lancer_rit

OTOH, Autocar does this shaking method (even putting one wheel on a incline) to fill up to max brim ! When they do their FE tests...

Funny ! Some one like ACI doing this is very funny. There are jigs available, which are connected in the fuel supply path (including overflow) which can let you run for exactly 1 or 2 liters. This will give a precise measure of FE. Some one like ACI, and as an organization, should use appropriate equipment and not rule-of-thumb methods like the regular user.

Originally Posted by lancer_rit

So this charcoal canister is part of the fuel supply path ?

If it is part of the path, then the petrol is going to go through the canister ( & hence the charcoal) each time you till fuel, and will get contaminated.

Originally Posted by 1self

The system sits alongside the fuel tank, at the rear of the vehicle.

Does any one have a figure / diagram / pic of this set up ?

[1self]

The first 2 pics are of my Sonata. I had the EVAP canister removed for blowing air. The last pic is a general diagram of the system. Please note that this is ONLY for PETROL vehicles. Diesel fuel does not need this system as it does not evaporate at room temperature.

[mempheS.D]

Sorry to be bumping up this thread, but can someone tell me whether one's running a risk by filling to the brim. On my weekly trip to the Shell fuel station earlier today, I noticed that approximately 20litres of fuel was filled into the tank after cut-off until the brim. I was shocked and started checking underneath the car whether there were any leaks?? None.

Is there a reason why the auto-cutoff is set so low? I did ensure that the filling was being done at slow speed to reduced the froth.

[Knight Rider]

Originally Posted by mempheS.D

Sorry to be bumping up this thread, but can someone tell me whether one's running a risk by filling to the brim. On my weekly trip to the Shell fuel station earlier today, I noticed that approximately 20litres of fuel was filled into the tank after cut-off until the brim. I was shocked and started checking underneath the car whether there were any leaks?? None.

Is there a reason why the auto-cutoff is set so low? I did ensure that the filling was being done at slow speed to reduced the froth.

As per the Owners manual,The fuel will expand if the temperature goes high and the auto cutoff ensures that there is enough space left out in the tank for this to be possible. I also used to fill the tank till the brim till I stumbled upon this information in the Manual.

[Blue Thunder]

Originally Posted by mempheS.D

... approximately 20litres of fuel was filled into the tank after cut-off until the brim...

20 litres is definitely not normal...must be something in your car causing the cut-off to get activated much earlier. Usually 2-3 litres can go in extra for a 35-liter tank.

[mempheS.D]

Originally Posted by Knight Rider

As per the Owners manual,The fuel will expand if the temperature goes high and the auto cutoff ensures that there is enough space left out in the tank for this to be possible.

That makes sense, and I should be careful about this. I hope I haven't caused any damage. I happened to read about the charcoal canisters further up on this thread, and although it doesn't sound like irreversible damage, I wouldn't want to run the risk of making a trip to the "Skoda" A.S.S when it can be avoided.

Originally Posted by Blue Thunder

20 litres is definitely not normal...must be something in your car causing the cut-off to get activated much earlier. Usually 2-3 litres can go in extra for a 35-liter tank.

I agree. it's not normal. Will wait and watch closely. Btw, the Fabia tank capacity is 45litres as per the manual. I had about quarter tank (10litres) in there before I refilled another 38litres.. If the tank capacity is 45 litres, where did the remaining 3 go??

[iSpoke]

Originally Posted by mempheS.D

On my weekly trip to the Shell fuel station earlier today, I noticed that approximately 20litres of fuel was filled into the tank after cut-off until the brim. I was shocked and started checking underneath the car whether there were any leaks?? None.

Is there a reason why the auto-cutoff is set so low? I did ensure that the filling was being done at slow speed to reduced the froth.

I suspect, while filling up the petrol the fuel pump nozzle might have pressed the valve inside the filler tube and that released the air from tank and allowed to accommodate this additional petrol.

Originally Posted by Knight Rider

As per the Owners manual,The fuel will expand if the temperature goes high and the auto cutoff ensures that there is enough space left out in the tank for this to be possible. I also used to fill the tank till the brim till I stumbled upon this information in the Manual.

You may happily fill-up the petrol upto the brim and release the air by pressing a valve, that should lower the level from brim. If you pip inside the fuel filler tube, there is a black button (valve), pressing it releases the trapped air from the fuel tank. Care should be taken not to top-up after this adjustment, else you will endup filling up to much of petrol (may be more than 45ltr).

Originally Posted by Blue Thunder

20 litres is definitely not normal...must be something in your car causing the cut-off to get activated much earlier. Usually 2-3 litres can go in extra for a 35-liter tank.

Originally Posted by mempheS.D

I agree. it's not normal. Will wait and watch closely. Btw, the Fabia tank capacity is 45litres as per the manual. I had about quarter tank (10litres) in there before I refilled another 38litres.. If the tank capacity is 45 litres, where did the remaining 3 go??

I already posted this caution note from Owner's Manual into the Fabia thread, may be it makes sense to have it here too.

Make sure that the valve is not pressed into the filler tube when inserting the pump nozzle into the filler tube. Otherwise you are unintentionally filling up the volume, which in case of heat can cause an expansion of the fuel. This can lead to an overflow of fuel or damage to parts of the fuel reservoir.

Simply Clever!

[CANPUSH]

Originally Posted by iSpoke

I already posted this caution note from Owner's Manual into the Fabia thread, may be it makes sense to have it here too.

I tried to search but could not locate the post.

Can you post the link?

[msaudf]

I'm sure everyone who drives have faced the same situation described in this tread of having filled inconsistent volumes of fuel with the auto cut off in play.

My cousin brother who lives in Coimbatore tackles this differently by allowing the cut off to come in play and fill up like normal and also by shaking and wiggling the car, but then after paying the bill he simply drives the car out of the fuel station and brakes wildly and simply goes back to fill up again. to my astonishment there was space in the tank for another 7 litres. the chap who was filling up just chuckled and said to me that this is his usual routine, and the first time he did this, he pulled away without paying for the first fill up he almost threw a stone at the car's rear windscreen, but then he simply returned and asked for another fill up, the poor chap thought that my brother had lost it and acted to fill up and even he didn't understand what was happening and checked for leaks under the car as it took in more fuel.
BTW my brother is very mileage conscious.

[woodcrawler]

Originally Posted by msaudf

I'm sure everyone who drives have faced the same situation described in this tread of having filled inconsistent volumes of fuel with the auto cut off in play.


BTW my brother is very mileage conscious.

msaudf, I'm sorry to butt into an old thread but I happen to also be a petroleum retailer besides other things I do.

The auto-cut off feature is there in the new dispensing units to ensure that the tank is not over filled. However, please remember each dispensing unit (brands) have a different sized nozzle. High speed dispensing units have wider nozzles to cater to trucks and buses that fill 200 - 400 liters at one go. Always stop next to the dispensing unit designated for cars in a petrol station, even if it means waiting a bit!

Though user manuals show a specific fuel tank capacity, usually on either side of 50 liters, there is a dead space of 20-25% more than the mentioned capacity. This is to allow expansion of vapour in hot weather. The first time the auto-cut off works it could be due to a mix of fuel and froth that come up as the tank gets full. You could stop after filling another liter or two after this point.

Of course, you can go on filling, ignoring the auto-cut off every time it cuts fuel dispensed but you will be overfilling the tank by 10-15 liters depending on the vehicle. If the fuel gauge is electronic it gets stuck till the fuel level reaches what is mentioned in the manual. It has been suggested to remove the key from the ignition when filling.

My Duster's tank can take 60-63 liters though the manual says the capacity is 50 liters as the capacity. Working out the FE of your car can be tricky then. When filling up I, now, wait for the first cut off, then fill up another 2 liters. The gauge will show 'full'. It works fine for calculating the FE.

There is no need to have fear of running out of fuel these days because our overzealous oil companies have ensured that there is a fuel station every few kilometers even if there are no hotels. You might go hungry but your car never will

[iSpoke]

Originally Posted by CANPUSH

I tried to search but could not locate the post.
Can you post the link?

here it is,

Originally Posted by woodcrawler

msaudf, I'm sorry to butt into an old thread but I happen to also be a petroleum retailer besides other things I do.

Great to know about your one of the profession. So now we can have reliable information about retails. The different nozzle size for heavy commercial vehicle makes sense, though was not aware it existed.

Originally Posted by woodcrawler

Though user manuals show a specific fuel tank capacity, usually on either side of 50 liters, there is a dead space of 20-25% more than the mentioned capacity. This is to allow expansion of vapour in hot weather. The first time the auto-cut off works it could be due to a mix of fuel and froth that come up as the tank gets full. You could stop after filling another liter or two after this point.

Of course, you can go on filling, ignoring the auto-cut off every time it cuts fuel dispensed but you will be overfilling the tank by 10-15 liters depending on the vehicle. If the fuel gauge is electronic it gets stuck till the fuel level reaches what is mentioned in the manual. It has been suggested to remove the key from the ignition when filling.

My Duster's tank can take 60-63 liters though the manual says the capacity is 50 liters as the capacity. Working out the FE of your car can be tricky then. When filling up I, now, wait for the first cut off, then fill up another 2 liters. The gauge will show 'full'. It works fine for calculating the FE.

Exactly for these reasons, Fabia (and may be VW cars) comes with a valve located just inside the filer tube that on pressing releases the air/fume. The only issue was that most owner remain unaware about this feature and those aware used it wrongly to fill-up extra fuel after pressing it!

I think it can be very well used to calculate FE. First let the pump-nozzle auto-cut, then top-up to fill up to the brim by whatever ways you prefer - wait or shake. Once you sure that tank is full, press the valve that should (somehow) make space and lower the fuel level. DO NOT FILL AFTER THIS. The manual does not list any serious disadvantages of it, but advisable to keep this volume free for fumes.

[Red Liner]

Bumping this thread up!

Guys,

Got a problem with the Figo I drive. Just got done with the 20k service. When I try and fill diesel, the car's auto cut off, cuts in within a minute and doesn't allow the nozzle to pump fuel in any more. So We have to over ride the cut off, and manually force feed fuel. Takes an awfully long time to do 45 litres.

This problem cropped up immediately AFTER the scheduled service. I want to know what could have caused this? Could fuel pilferage in some way have caused this?

I have topped up the tank twice over to rule out air lock issues. Would appreciate some feedback.
__________________

[joybhowmik]

Originally Posted by Red Liner

When I try and fill diesel, the car's auto cut off, cuts in within a minute and doesn't allow the nozzle to pump fuel in any more.
I have topped up the tank twice over to rule out air lock issues. Would appreciate some feedback.

Is it the same dispenser both times or a different dispenser?

[Red Liner]

Originally Posted by joybhowmik

Is it the same dispenser both times or a different dispenser?

Different dispensers, the issue persists only with my car. No other car behind or ahead of me has this issue.

And it's cropped up dead after service. Not very inspiring.