Roger:
I have exactly the same situation with my 1992 Plus 8 with twin cat
converters. This is a Bill Fink California Emissions legal car with an
evaporative emissions canister between the fuel tank and the intake system.
The problem you describe is reasonably typical of all California vehicles
built since the late 80's. Basically the fuel tank is a sealed unit (sort
of), and as the fuel is burned off, a slight vacuum is formed. I too hear
the tank expanding when I take the fuel filler off (I also can hear the air
rush in on my Mercedes, my wife's Honda CRX and my 1889 Chevy 4-wheel drive
pickup).
Early in the game here, we too had problems in general with spitback from
the fuel tank while filling. This appears to be reasonably solved as the
technology of fuel filler nozzles has improved in recent years to cope with
various emissions requirements.
Short of disabling and opening up the line between the fuel tank and the
evaporative emission canister to the atmosphere (and plugging the end at
the intake) I think it is a situation we have to live with with all of the
emissions control stuff we have been saddled with (admittedly it has
definitely helped improve air quality in the San Francisco Bay Area over
the past 20 years).
Should anyone else have any home remedies that have succeeded I also would
be interested.
An interesting symptom reduction device I saw last month when I was on the
Lancs & Lakes Opening run north of Liverpool was a new 4.6 owner (Ian
Naisby) who had crafted a "bib" out of innertube material. This "bib"
stretched over the fuel filler pipe and led down the rear panel to just
below the rear bumper. If fuel happened to spill over, it would run down
the "bib" and dissipate on the ground without touching the paintwork.
Unfortunately I cannot make use of this personally since on the US spec
cars the fuel filler is located under a locking door and there is not
enough filler stem protrucing to secure the "bib".
Regards,
Phil Fisher
1970 4/4 4-seater (no evaporative canister but still will spit back fuel if I'm
not careful on filling)
1992 Plus 8 twin cat
==============================
> Hi All
> I have just taken delivery of a new 4.6 +8 and I have the following problem,
> When I open the petrol filler cap, air rushes into the tank and I can hear
> the tank expanding. Also, when I fill the car up, when the pump nozzle is
> removed from the filler cap, petrol pours back out of the tank.
> I seems as if there is no breather for the fuel tank. Does anyone know
> where the breather is? I have removed the spare wheel and looked at the
> tank, but can not see an obvious breather pipe.
> Help!
> Roger Burtenshaw
> 1956 +4
> 1999 +8
|