petrol smell/carbon filters?

[911hillclimber]

1973T with injected 3.2 engine. Been in the car for 15 years or so.

When accelerating hard, tank 1/2 full (say) I get a strong smell of petrol.

This is a new smell, not noticed in the years gone by.

Car has the 73 carbon filter piped to the top vent of the tank, to the filter under the screen scuttle (stock location) and then a long tube all the way down to the n/s battery box and out under the wing to vent to atmosphere, much as the standard routing.

So, engine under load, lots of fuel being pumped to the injectors, and excess being blown back to the tank return just by the tank output. Normal injection fuel circuit.

No leaks at the tank/pump by the steering cross member (have removed the stone guard to check with torch).
No leaks on the mighty 3.2 engine (all stock pipes and tubes)

Thus is it the carbon filter kaput/exhausted or what?

I also get this when filling up, again it would be the venting of the tank to the filter.

Any thoughts please?

[Nige]

I removed my charcoal filter on my 3.2 and did notice a marginal whiff but nothing that bothered me. I plugged up the end ends.

One hose should vent into the airbox, I assumed the other end just went to the tank? There is also the expansion tank under the front wing that sits on top of the water res, there is also a small one (about the side of a extra large Yorkie bar) that is usually strapped to the filler neck inside the luggage comp.

I'm guessing some piping has come adrift or split.

This is a standard 3.2, but your's may not have had all the vent stuff transferred over when the engine was changed.

[911hillclimber]

The real 3.2 has quite a lot of cans/tubes etc, the original 2.4T on carbs had a very simple circuit that has worked for many years. Maybe it is just the fuel blowing back into the tank which is 1/2 full or less and it generates a lot of fuel vapour that simply gets past the carbon filter up by the fuel filler.
Not a fuel line leak as everything is bone dry.

More irritating than anything, but can't be right.

[Gary71]

Did you put the fuel cap on straight

I've done it before when only half the bayonet is engaged and it stinks.

[911hillclimber]

I thought about that but thought I would never do such a thing....
but will check in the morning!

Not sure I will admit to that, but good thought.

[JohnS]

Check the gasket on the filler cap. I had this - a split in the gasket created a very nasty petrol smell in the car. Made up a new gasket and smell gone.

[911hillclimber]

Thanks, will check, but cap screwed-on tight Gary!

Filled the car up to +3/4 full and not a smell static or running, cruising or accelerating hard, (etc).