It must be possible to totally solve this problem. :slayer::slayer::slayer:


From reading old threads it seems the problem began to appear in cars that been bought new and got worse and worse.


A few years ago I got the impression my car subsequently filled better after I washed petrol down the breather slots rather than down the usual filling hole. Is it possible the vent tube gets blocked up with residue??

Do people have any theories as to why these cars are so bad at filling up?

Too tight of a filling hole.... trap door causes issues?

Other cars i find maybe a slightly more sloppy fitting fuel.nozzle and maybe that 1mm(squared) gap may allow that XX% flow of air out.....

Obviously i find really empty tanks are much worse.... which again points to air.....

Ziggy

Ziggy122 said:

Too tight of a filling hole.... trap door causes issues?

Other cars i find maybe a slightly more sloppy fitting fuel.nozzle and maybe that 1mm(squared) gap may allow that XX% flow of air out.....

Obviously i find really empty tanks are much worse.... which again points to air.....

Ziggy

Click to expand...

Fiat have designed a very complicated filling method. I am assuming it should work correctly and there is a solvable problem.


There is no way my car was delivered with the current filling situation.


Edit: According to the utubers poor tank filling can be related to the evap system, they are saying we are not supposed to vent the air out of the tank as we fill it with petrol. They say the charcoal canister can be blocked up and need replacing.

judderbar said:

Fiat have designed a very complicated filling method. I am assuming it should work correctly and there is a solvable problem.


There is no way my car was delivered with the current filling situation.


Edit: According to the utubers poor tank filling can be related to the evap system, they are saying we are not supposed to vent the air out of the tank as we fill it with petrol. They say the charcoal canister can be blocked up and need replacing.

Click to expand...

They do over time break down and become solid which could cause breathing issues for it...

Never ever heard of it on failing.....
But maybe whip it out and give it a shake?

Ziggy122 said:

They do over time break down and become solid which could cause breathing issues for it...

Never ever heard of it on failing.....
But maybe whip it out and give it a shake?

Click to expand...

charcoal canister is fine I found today. But there is a crash/rollover check valve just under the filling cap which the two top tank vents connect to and then the other side of the valve is the charcoal canister. Very poor flow thru that valve.........

judderbar said:

charcoal canister is fine I found today. But there is a crash/rollover check valve just under the filling cap which the two top tank vents connect to and then the other side of the valve is the charcoal canister. Very poor flow thru that valve.........

Click to expand...

Ooooo... did u manage to make it better?

I had the filler neck off ages ago on mine to get rid of the soil that rots the archs out....

Im probably due a clean again.....

Ziggy

Ziggy122 said:

Ooooo... did u manage to make it better?

I had the filler neck off ages ago on mine to get rid of the soil that rots the archs out....

Im probably due a clean again.....

Ziggy

Click to expand...

Pretty sure there is a float valve in that liquid vapour separator just below the filler cap connected to the 3 tubes. It is on my list of things to do to cut it open and see what is going on. Details are in the evap thread.

judderbar said:

It must be possible to totally solve this problem. :slayer::slayer::slayer:


From reading old threads it seems the problem began to appear in cars that been bought new and got worse and worse.

Click to expand...

Success?! I changed the filler pipe with one from a 25,000km car and put in 40 litres yesterday with the petrol gun in a normal angle and at full speed. Totally no problems. :slayer:


I will cut the old one apart and see why it was so bad for filling

Nothing obviously wrong with the old filler pipe.

The pipe looks like this drawing inside.

judderbar said:

Nothing obviously wrong with the old filler pipe.

The pipe looks like this drawing inside.

Click to expand...

Just a thought but if you brim the tank full then petrol will go down the breather pipe and fill the U bend up with petrol which will stay there.

The next time you put petrol in the air has no where to go causing a backup of petrol coming in therefore triggering the pump pistol ????????

Italian Job said:

Just a thought but if you brim the tank full then petrol will go down the breather pipe and fill the U bend up with petrol which will stay there.

The next time you put petrol in the air has no where to go causing a backup of petrol coming in therefore triggering the pump pistol ????????

Click to expand...

Well it is true the breather tube always has petrol in it when I take it off the filler pipe. Maybe I just finally emptied it after about 5 times taking the thing off?


However what stops the flow of petrol from a half filled tank into the breather pipe when you go around a corner?

judderbar said:

Well it is true the breather tube always has petrol in it when I take it off the filler pipe. Maybe I just finally emptied it after about 5 times taking the thing off?


However what stops the flow of petrol from a half filled tank into the breather pipe when you go around a corner?

Click to expand...

Nothing is stopping it, that could be why you always find petrol in the breather pipe.

Is it possible to eliminate the U bend in the breather ?????

Italian Job said:

Nothing is stopping it, that could be why you always find petrol in the breather pipe.

Is it possible to eliminate the U bend in the breather ?????

Click to expand...

The filler pipe connection is too low for the flexible breather. If you raise the breather it crushes the bend as it connects to the filler pipe. It would need a hard elbow fitted to the filler pipe. Since that is a modification of the fuel system I was not wanting to go there. Additionally the breather exits the fuel tank and bends down to a clip on the main filling pipe. It seemed like Fiat really want that to be a U bend full of petrol but Grand puntos dont have it.

However it could be the flexible breather sags down with age and adds 2 cm of extra U bend which then creates this problem.

Maybe the petrol tank has been bent upwards by hitting snow??

I am fairly sure this problem did not exist on the new punto

Im glad you have resolved your problem, im just trying to work out why Fiat used that U bend !!!!!!