HELP On fuel tanking problem

[twigmeister]

Victim: Twingo RS 2009
Problem: With indicator on reserve only 35 liters or less can be tanked at different stations
Done: Filling neck is replaced with result 1 time 43 liters and the problem returned
Diagnose: I believe the air release system is not working, but have no clue what to do next

The Twigmeister
https://www.youtube.com/watch?v=yFH2ynoI_QY

 

[flowerpowerdave]

youve got too much time on your hands! lol....the devil will find work for idle hands to do..

 

[oscar]

i read this and basically got lost around halfway through it, what's the question here exactly? all i'm picking up, is that you have had a new filler neck on your twingo and now it's not filling up correctly?

it sounds like the pressure release valve is blocked or malfunctioning. as you're pumping petrol into the tank, there has to be some way for the air in the tank to escape. if the pressure release valve isn't working, pressure builds up in the tank, causing the pump to stop pumping.

 

[twigmeister]

i read this and basically got lost around halfway through it, what's the question here exactly? all i'm picking up, is that you have had a new filler neck on your twingo and now it's not filling up correctly?

it sounds like the pressure release valve is blocked or malfunctioning. as you're pumping petrol into the tank, there has to be some way for the air in the tank to escape. if the pressure release valve isn't working, pressure builds up in the tank, causing the pump to stop pumping.

The tank was not filling up correctly before replacing the filler neck. After replacement of the filler neck, the air was released and filling up went correctly for 1 time with 43 liters.
Now the problem returned and it looks like the pressure release valve isn't working correctly. So far you are on the right track.
At this moment it is not clear how the pressure release system exactly works, till now I thought this was done 100% by the filler neck. After viewing images of fuel tanks it looks like every tank has this pipe on top to release air but where is the release valve located?
Is the release valve located on the fuel tank or is it connected with a tube to the filler neck and released at the filler neck?

TX for your response

 

[twigmeister]

youve got too much time on your hands! lol....the devil will find work for idle hands to do..

The devil kicked my ass and made me reduce the amount of characters hope it is better now.

 

[twigmeister]

I will not maintain this thread anymore, lack of response.
You can always pm me on this topic.

 

[singlespeed]

Hidden in the shadows, slightly left and behind the engine lifting bracket, there's a valve which has (or at least had) a short hose connection onto the manifold plenum chamber and an electrical cable plugged into the top of it.

This has something to do with fuel vapours but I'm not sure if it would play a part in smooth refuelling.

 

[Dazza1]

I always used to have problems filling my old 133 up it kept clickin on the pump think it was full when it wasn't

 

[user 980]

I always used to have problems filling my old 133 up it kept clickin on the pump think it was full when it wasn't

This x 1000

No matter how you used the nozzle, not inserting all the way :lol: it still didn't make any difference. In 2 and a half years of ownership only once did I manage to get over 2/3rds full!

 

[twigmeister]

Thanks for your reaction. The filling has nothing to do with the engine although the picture looks nice.
2 days ago I discovered the existence of a plastic valve, it is located in the inlet of the tank reservoir.
Translated from Dutch it was called limiting valve tank. It is designed to limit the tank on 40 liters while it is a almost 50 liters by experience. Hope to get this dammed limiter removed next week and keep you posted.

Twigmeister

 

[JMR]

I always used to have problems filling my old 133 up it kept clickin on the pump think it was full when it wasn't

Yep same here.
And alternatively, how many times did you end up with fuel soaked trainers when it overspilled?

Me a couple. :lol:

 

[maggi200]

Same here. Poured straight out once or twice.

 

[Liam24]

Mine does the annoying clicky thing where it thinks it's full everytime I fill up. What causes this?

 

[oscar]

the first thing you have to understand is that when you put petrol into an empty or low tank, you are displacing a lot of petrol vapors inside of the tank and this is handled by the EVAP system (known in the old days as a charcoal canister). When you put fuel in, the liquid level rises displacing the petrol and air vapors inside the tank to the EVAP system which can only hold so much at a given time. if this wasn't in place, when you filled your tank up full ... the lower the fuel level got, the pressure would get negative and your fuel tank would crumple in on itself. there is a pressure relief valve connected to the fuel filler neck which opens to allow in fresh air to enter the tank at certain vacuum to maintain a constant pressure inside of the tank for safety reasons as the fuel level lowers and it only vents one way > inwards into the tank. this could / can allow dirt to be introduced into the system and could block the EVAP lines.

remove the EVAP line leading from the tank to the EVAP canister > blow compressed air through to clean any debris out. your EVAP system can fail and not throw up any fault codes, all this is down to something silly like a blocked EVAP hose which will lead to complications like CLICK CLICK CLICK at the pump.

that is what neil was referring to, it's the root cause for these kinds of problems.

 

[twigmeister]

the first thing you have to understand is that when you put petrol into an empty or low tank, you are displacing a lot of petrol vapors inside of the tank and this is handled by the EVAP system .......complications like CLICK CLICK CLICK at the pump.

that is what neil was referring to, it's the root cause for these kinds of problems.

Dear Oscar,
You can talk about EVAP system and blowing with compressed air but it will solve nothing. Last week my car came back from the Renault garage and they spoke about blowing with compressed air and changed the valve at the intake of the fuel reservoir.Tank proces went the same like always with 20km on reserve 38.8 liters and 1st click around 35liters. Also the first bar was burned at 87km while I drove 170km more then once after a garage visit. I have attached some resized pictures of this shady valve thing located at the inlet of the tank reservoir, this thing is very SECRET and do not speak about it very hash hash.
Hope to get this filty thing out next week and keep you posted on the results. What would be the English term for the white bandit shown on 2 pics?

Can anyone tell me if the marked tube is called the EVAP line?
If I am correct the system runs with under pressure, where is the air intake at the upper question mark?
Is it possible fuel gets into the cannister part of the fuel neck and disturbs the proces?
My picture dir can be listed if you are interested, zie pic dir

 

[oscar]

the first thing you have to understand is that when you put petrol into an empty or low tank, you are displacing a lot of petrol vapors inside of the tank and this is handled by the EVAP system .......complications like CLICK CLICK CLICK at the pump.

that is what neil was referring to, it's the root cause for these kinds of problems.

Dear Oscar,
You can talk about EVAP system and blowing with compressed air but it will solve nothing. Last week my car came back from the Renault garage and they spoke about blowing with compressed air and changed the valve at the intake of the fuel reservoir.Tank proces went the same like always with 20km on reserve 38.8 liters and 1st click around 35liters. Also the first bar was burned at 87km while I drove 170km more then once after a garage visit. I have attached some resized pictures of this shady valve thing located at the inlet of the tank reservoir, this thing is very SECRET and do not speak about it very hash hash.
Hope to get this filty thing out next week and keep you posted on the results. What would be the English term for the white bandit shown on 2 pics?

Can anyone tell me if the marked tube is called the EVAP line?
If I am correct the system runs with under pressure, where is the air intake at the upper question mark?
Is it possible fuel gets into the cannister part of the fuel neck and disturbs the proces?
My picture dir can be listed if you are interested, zie pic dir

dear oscar? bit cheeky.... i fixed one of these problems on a 2007 megane last week. same fuel tank, same evap system and the same symptoms described. note that i said system, evap system runs from the very outside of your fuel tank all the way to your fuel rail. it's a very long system, inspect further as it's not rocket science. there is a blockage somewhere exerting a back pressure - nothing else is causing it, as there is nothing else in the system to cause it.

strangely enough, the problem was cured on the megane by unblocking the evap system after ensuring the operation of the PRV (pressure release valve) was adequate.

 

[twigmeister]

this look like mis communication, can you give a pic of evap cannister you mentioned?
since you speak of all the way to the fuel rail i guess the evap cannister is under de hood?
my problem was also solved for a short while, but came back after 3 gas station visits.
after replacing the fuel neck someone spoke about fuel on a place it should not be.
true about rocket science but i am an computer enigeer and have to rely on Renault people whom charge 100+ Euro an hour. Taking fuel out and in, 200euro, so ride it till reserve indicator and spend 65 euro of fuel.
it is terrible when you are depended on the big brand dealers and these rates and lacking the right expertise.
Thanks for your view on this topic.