ianellison

Help needed! After a short drive and standing overnight I get slight petrol smell in the luggage bay concentrated under the carpet adjacent to the fuel filler point. After a long run I get a much stronger petrol smell after the car has stood overnight both under the bonnet and in the cabin.

The filler neck, fuel return valve and a pipe under the petrol header tank had been replaced previously as they were damaged. The header and petrol tank have now been pulled forward and all connections checked and tightened - there was no sign of leakage anywhere!

I am told that there is a solenoid at the engine end of a fuel vent pipe which is supposed to open whilst driving to evacuate fuel fumes. I wonder if this is not working and the fumes build up after a long run and gradually seep out overnight? Any experience of this or suggestions welcomed.

ianellison

Would also be very interested to know if your 964 has any noticeable fuel smell in the front luggage bay after standing for a few hours or overnight ? Or is there non at all?

Superunknown

None at all for me. Have you checked this:
http://www.porsche964.co.uk/technical/fuel.htm

Red rooster

If the vent valve stops working so will the motor ! That link is good. There has been all kinds of playing around with the gas tank.
I had some of that smell problem but found that the fuel feed at the bottom of the tank had a slight leak . A replacement tank fixed that !

Geoff

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KS400200 , the oldest 964 on Rennlist , unless you know differently !

ianellison

What is the function of the 'carbon filter' on the fuel vent side located under the offside rear wheel arch according to Adrian's book? If this is activated carbon it should absorb fuel odour - could it be blocked or depleted perhaps - anyone know?

ianellison

Thanks superunknown. I do have the latest filler neck fitted.

Smokin

I've got the same issue. I replaced the filler neck and cap and still have the smell. It's not overpowering but you have a hint of gas mainly in the front boot but also a little in the cabin. I just tell people that it's the starting procedure... j/k

ianellison

Thanks Red Rooster. My garage pulled the tank forward (not out) yesterday and checked all the connections which were OK. Do you think that they could have got to the fuel feed connection if they didn't have the tank right out?

Red rooster

What is the function of the 'carbon filter' on the fuel vent side located under the offside rear wheel arch according to Adrian's book? If this is activated carbon it should absorb fuel odour - could it be blocked or depleted perhaps - anyone know?

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The carbon filter takes fumes drawn from the top of the tank and air from the lower pipe at the bottom of the canister and feeds both to the vent valve that is just foward from the throttle . The DME turns the vent valve on at appropriate moments to use fumes as a partial fuel source .

Just another bit of the emmission control system. If there is a block in the air feed/tank fume supply the DME doesnt know and keeps on using the zero fume supply !! Thats causes a severe running problem !

Hope that helps .

Geoff

--------------------------------------------------------------------------------
KS400200 , the oldest 964 on Rennlist , unless you know differently !

Red rooster

Ian ,

Did they get underneath and take the pump plate off to check the bottom of the tank ? Thats where the fuel pipe work is .

Geoff

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KS400200 , the oldest 964 on Rennlist , unless you know differently !

Nader Fotouhi

Where do you access this plate? Is it clearly visible if put the front on the jack stands and get unedrneath the boot? I have the same issue and all the hoses and connections visible on top appear to be dry.

Red rooster

Yes, the sort of triangular plate is underneath , situated on the floor , positioned under the back of the tank . Its held by a few 10mm bolts .


Geoff

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KS400200 , the oldest 964 on Rennlist , unless you know differently !

JasonAndreas

It's the freshly painted black cover below

anewbill

I also have the smell. More so with a full tank. My filler neck has also been replaced.

911URGE

I had a similar issue with a different fix in my case. See THIS post.