Gas Pump Problem-Evap Emmissions Check Valve

I haven't had a problem yet with the nozzle shutting off and we have vapor recovery in CT. And my gas mileage is identical...

 

I can't help directly, but, if you do something that puts a high vacuum on the tank itself, the problem isn't that you might suck some fuel out into the intake tract -- the problem is that you might implode the tank (so you are right to be cautious).

When you say that you found the 2-way valve installed backwards are you basing that on the visual comparison of what you have to the OM figure and the SPC figure?

I'm the first to say that some of the F technical English translations are downright terrible, but "2-way" implies to me that there is flow allowed in both directions under some conditions (i.e., it isn't a simple one-way check valve) -- have you tried sucking and blowing (no jokes please!) both gently and strongly on each hose connection port of the 2-way valve?

PS I'm a little doubtful that the entire air volume of the empty tank is forced thru those small lines (or that they could handle such a high flow rate or that the designer wanted this displaced air running into the intake tract and thru the non-running engine). It would be more straight-forward if the displaced air was meant to come up the ~19mm line that runs parallel to the large fill line -- are you sure this ~19 mm line is unkinked/unblocked? Also, where it rejoin the main fill line near the fill cap -- is this above where the end of the filling station nozzle reaches?

 

The problem is, I believe, caused by the cast fuel filler used by Ferrari that is narrower than the fabbed steel ones used in other brands. This narrower inlet tends to cause some gas/fuel/petrol (depending on your accent ) to splash around and back at the nozzle. The more sensitive ones detect this and shut off.

My Mondial t does it, my 355 did it. I do have a local Shell gas station here in Simi Valley where the number 5 pump is better than the rest. I always wait for that one.

FWIW my wife's Mazda MPV is just as bad as the Ferraris - it has a 90 degree bend in the filler nozzle just after where the pump spout would reach. The Miata was perfect however.

The check valve in your car may be the wrong way, but I don't think it will make any difference. Oh.... and your mileage will still suck, although 16 is pretty good if it's a 95

 

Are these valves on 360's as well, and if so where? Mine takes forever to fil and I would like to check this out. Thanks.

 

The picture shows the valve inverted from the image in the service manual. Can someone confirm that this is correct? I was getting the "WOOOSH" sound when I opened my fuel cap, but starting today, I no longer hear it. I have not changed anything. I also have a 1997 F355 Spider, but my valve is facing the opposite direction of the one in the image.

 

We've seen this problem too with 360's where it ended up being the activated charcoal filter too plugged up. That is, with all valves working properly there was not sufficient flow through the canister to vent the tanks while filling up with gas.

Also on the 360 there are check valves at the top of each tank. If you smell fuel, chances are on or more is cracked. Ferrari has an updated version. The whole spider top section has to be disconnected and moved up with a hoist to get to them on the spider model!
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at the risk of being irrelevant, i have similar problems fueling my 328.
most filler hoses will try to spill fuel back up the neck if i try to pump too quickly.
i cannot use the autofill feature at any gas pump. it will simply kick off.
i really hate spilling fuel on the car or letting it run down the cavis hose.
must be a "ferrari" thing. interesting though, my gmc pickup has the same problem.