Problem in filling petrol with "Auto Cutoff" feature

[DerAlte]

Nothing has changed in the behavior of your car. The culprit is the nozzle at the filling station, not anything in your car's tank or filling pipe. The nozzle back pressure sensing is awry. If you go to a filling station with new nozzles, this will not happen.

[lancer_rit]

Originally Posted by DerAlte

Nothing has changed in the behavior of your car. The culprit is the nozzle at the filling station, not anything in your car's tank or filling pipe. The nozzle back pressure sensing is awry. If you go to a filling station with new nozzles, this will not happen.

Thanks DerAlte. The issue is that it happens in more than 1 or 2 pumps, and I do see other cars using the auto-cutoff as expected in the same station... But it may still be that it has nothing to do with my car, just am not sure about it!

[mempheS.D]

This makes me a recall an incident at Shell bunk on Vittal Mallya road about a month ago. I had asked for a tank full, and the boy just slips the pipe in while I just ogle a sparkling Harley that had just arrived at the pump. About 2 mins later, I hear the sound of water dripping on the floor and to my surprise, the tank was filled over the brim and the precious fuel had already started pouring all over. I was spell-bound for a few seconds until a screaming voice escaped my throat which sounded the alert that was necessary. The guy came in stopping the gun ASAP, murmuring something in the local lingo. Not my worry cos I was sure NO MATTER WHAT I ain't going to pay a penny more than what went into my tank. So I pull my car over the to the side, and walk to the cash counter. To my surprise, the guy received me with a pleasing smile and asked, "Sir, what's the last rupee amount you saw on the filling machine?". I replied, "What I remember seeing is that at Rs. 2300/- the petrol had started overflowing". He responded, "It's our mistake, so you can pay Rs. 2000/- if that's ok with you." Obviously, for that attitude, my response with a grin was, "SURE!"

[pramodkumar]

How can someone not mention such a simple cause? Guys this is very simple issue. The furl has vapourizing properties and all the cars have a lid to prevent the vapors from escaping. Sometimes when you continously run the car on low fuel or may be keep the car parked for long with low fuel the tank is filled with vapors and while filling this vapor escapes some times with a gushing sound and sometimes without it depending on the pressure this causes the pump to cut off to avoid spilling. I know how anoying this could be when there is a huge crowd waiting behind you to fillup. Just go to a pump which is less crowded and fillup patiently.



Pramod

[lancer_rit]

@pramodkumar, hmm that could be really the case. Sometimes, to do full tank fills, I am driving to E or below E (also to reach the right petrol pump!). Let me change over to filling up from 1/4 and see if the behavior changes!

[IQBAL VEERJI]

Originally Posted by RajeshK

Dear All,

I am using a Santro zip plus 1.1LP which clocked 52K kms now. Few days back, I went to a petrol pump and asked them to fill full tank with autocut feature in the filling pump equipment. I already have half tank petrol, but to my surprise the device stoped just after filling only 5Ltrs. I asked them to retry, but stopped immedietly. So there is a problem either in the device or my tank. So used manual mode (Seek and try method..!!) and filled the tank with another 15Ltrs.

After some days, again this experience repeated this time autocut went off a little later, 7Ltrs. . So realised...problem is with me only...The autocut feature is not working in my vehicle at all.. But fortunately it accepting petrol..!!

Can any one throw some light on this issue...? Any possible way to check for any issue..? I am not able to see any issue in the tank with my naked eye.

Thanks
Rajesh

Yes dear it happens in my Alto as well as Camry.But in ALTO after autocut of flow of petrol the guy started filling it manually with the flow cutting off frequently but to my surprise about 5 ltrs of petrol was filled and I could see the level till the neck of the filling point.
In Camry I cant do this as it has got a flip disc at filling point which covers up the filling hole once the filling hose pipe is removed.

[Aroy]

To avoid excessive back pressure ensure that the air venting pipe (normally soldered inside the filler pipe is not clogged. If it is, there is no where for the air to escape while fuel is being filled, and a lot of back pressure will develop, triggering the auto cut off earlier.

Narrower filler pipes came after unleaded petrol was introduced. The older nozzles and the filler pipe were broader, so to prevent leaded petrol; which had broader nozzles; from being filled in cars meant to run unleaded petrol - BS-II onwards, narrow openings were introduced in cars, and narrower nozzles in the pumps.

[xingamazon]

Originally Posted by lancer_rit

Thanks DerAlte. The issue is that it happens in more than 1 or 2 pumps, and I do see other cars using the auto-cutoff as expected in the same station... But it may still be that it has nothing to do with my car, just am not sure about it!

There is one trick that my driver always does.
He shakes the car to an exten that it kind of wobbles. He says this reduces the bubbles in the tank and will take in more petrol.

I am not sure how far that is true but I have see it taking more petrol in after shaking, why dont you try that out too.

[Pancham]

Originally Posted by xingamazon

There is one trick that my driver always does.
He shakes the car to an exten that it kind of wobbles. He says this reduces the bubbles in the tank and will take in more petrol.

I am not sure how far that is true but I have see it taking more petrol in after shaking, why dont you try that out too.

yes. I have seen people doing this. Never knew it was due to this though it has been a very old practice.

[VANOS]

Originally Posted by Pancham

yes. I have seen people doing this. Never knew it was due to this though it has been a very old practice.

What i feel is that shaking the car releases the taped air in the tank so that it can hold more fuel. I also feel that these air traps are done on purpose by the factory so as to allow for expansion of fuel at high temperature. Hence i would not advice it unless you are going on a long trip . This is just my theory, i got no facts to back it up.

[lancer_rit]

Originally Posted by xingamazon

There is one trick that my driver always does.
He shakes the car to an exten that it kind of wobbles. He says this reduces the bubbles in the tank and will take in more petrol.

I am not sure how far that is true but I have see it taking more petrol in after shaking, why dont you try that out too.

Well, its not that I am trying to squeeze in 5% more fuel - I am struggling with the auto-cutoff going off even with the fuel tank 60% empty, for example... So, my needs are simpler :-)
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...

[lancer_rit]

Originally Posted by lancer_rit

@pramodkumar, hmm that could be really the case. Sometimes, to do full tank fills, I am driving to E or below E (also to reach the right petrol pump!). Let me change over to filling up from 1/4 and see if the behavior changes!

Well, I tried filling at 1/4 or 1/3 full (as per the fuel gauge), but the auto-cutoff still fires way too early. Sometimes, as soon as the attendant moves away :-(

[1self]

The problem is with the charcoal canister. Have that checked, associated piping cleared of blocking charcoal powder & cleaned with compressed air. That will solve your problem. This may also involve putting fresh charcoal powder in the canister.

[lancer_rit]

Originally Posted by 1self

The problem is with the charcoal canister. Have that checked, associated piping cleared of blocking charcoal powder & cleaned with compressed air. That will solve your problem. This may also involve putting fresh charcoal powder in the canister.

Thanks.
So this charcoal canister is part of the fuel supply path ? Do I have to go the A.S.S. or its simple to do at any workshop - I mean I have not any previous idea about this, so what needs to be dismantled ? Where would this canister be located and how to access ?

[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.

The system sits alongside the fuel tank, at the rear of the vehicle. I think very few workshops or even A.S.S. know this problem simply because India still has relatively milder vehicular emmision standards as compared to the western countries. Abroad, charcoal contamination leads directly to a 'check engine light' & a fault code is lodged by the car ecm.
The A.S.S. will know how to open the canister & blow air through the system.