Slow fuel fill

[Speedy Squirrel]

Do all model year turbos have a slow fuel fill (nozzle shuts off when filling)? Is there a restriction of some kind in there?

[philip j]

Turn the nozzle 180* when inserting. Philip

[porche]

+1

With some nozzles you may still need to regulate the fuel flow by hand at less than full. The automatic fill feature may or may not work all the time.
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[Speedy Squirrel]

Thanks. I too have discovered the workarounds. I was wondering if anybody had figured out the root cause of this annoying behavior.

[porche]

Thought I read somewhere it had to do with the angle of the pipe to the tank. It is pretty flat in the area under the fuse box on our cars.

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[Tt surgeon]

Originally Posted by philip j

Turn the nozzle 180* when inserting. Philip

Great tip!

[Roby466]

The 911sc I use to have had the same problem, my current 930 has a pin a few inches in the pipe that prevents the nozzle from being fully inserted (causes a bit of spraying out of the pipe as well). It was probably there to prevent a suction hose from being inserted. While the 930 (with the pin) still does it from time to time, the 911sc (without the pin) would allow the nozzle to be inserted fully and would trigger the stop constantly. Might have something to do with that pin. My 930 is a grey market, do US cars have the pin as well?

[Dai]

My 81 930 Canadian car has one of the pin as stated above and it does prevent the nozzle to be fully inserted. It works great except you have to watch toward the end that you don't over filled.

[lee88]

The 180 trick doesn't always seem to work for me so I just regulate by hand and pump a little slower. I can usually pump at 50-75% of full flow. Happens both on my 930 and my 993TT FWIW so the filler neck design must not have changed much across different generations of air-cooled turbos (and other 911s).

[911nut]

Originally Posted by Speedy Squirrel

Thanks. I too have discovered the workarounds. I was wondering if anybody had figured out the root cause of this annoying behavior.

Inadequate venting due to a restriction in the vent line or evap system is usually the cause of nuisance premature shut-offs. If the air in the fuel tank is venting through the filler instead of the vent valve(s) or vent line, fuel wells up in the filler neck and triggers the nozzle to shut off.
The fuel tank in my car has only one vent valve. It probably needed two.
My '81 SC had the same issue. I guess customers didn't complain enough about it.

[speednme1]

Originally Posted by 911nut

Inadequate venting due to a restriction in the vent line or evap system is usually the cause of nuisance premature shut-offs. If the air in the fuel tank is venting through the filler instead of the vent valve(s) or vent line, fuel wells up in the filler neck and triggers the nozzle to shut off.
The fuel tank in my car has only one vent valve. It probably needed two.
My '81 SC had the same issue. I guess customers didn't complain enough about it.

That sounds about right...one way I've found to avoid the issue is to stop topping off during fuel fills. Trying to squeeze that little extra in seems to have a negative effect when refilling comes around. Funny thing is my daily does the same thing..I've stopped topping off and it seems to alleviate the issue.

[911nut]

Originally Posted by speednme1

That sounds about right...one way I've found to avoid the issue is to stop topping off during fuel fills. Trying to squeeze that little extra in seems to have a negative effect when refilling comes around. Funny thing is my daily does the same thing..I've stopped topping off and it seems to alleviate the issue.

Nozzle shut-off when topping off is by design. When the filler neck fills with fuel (which happens when the vent tube in the fuel tank is submerged; it will stop venting the tank at this point), it will shut off the dispensing when the fuel wells up to the nozzle. The rule for newer cars is 2-3 clicks. Any more and it will end up in your shoes or, God forbid, in the charcoal canister (necessitating a new canister) in extreme cases.