Smells of petrol

[PXC]

Hi

ive just bought a TR3A from another member, it’s unrestored so needs a bit of work, but driveable. My immediate problem is that it smells strongly of petrol when parked in the garage overnight. I have traced the fuel lines as far as I can and found nothing. I suspect a porous tank, which would be unfortunate, but by nose, the strongest smell seems to be from under the bonnet. When the car arrived a few days ago it had little fuel in it, but the smell was there.  I have subsequently filled it up, but that hasn’t made it any worse. 
 

im probably going to ask TR Bitz to look at it after the BH, but in the mean time

any ideas please?

thanks

paul

[RogerH]

Hi Paul,

I'm sure you have looked at all the pipes for obvious leaking.

Replace ALL the rubber connections with R14 rubber piping - they may be porous.

The float chambers are vented to atmosphere, so you will get some smell from there

The older carbs H4 etc  can leak from the main jet body underneath the carb where the needle goes. There is a cork gasket that dries up and then leaks.

This can be replaced by a modern (Viton) equivalent.

Do check the underside of the fuel tank. As you mentioned they can become porous and the smell can travel.

Vent the garage  

 

Roger

 

 

 

 

[BlueTR3A-5EKT]

Does the car have a petrol tap?   Left side where the front to back fuel line enters the engine compartment before the pump on the engine block.   These weep.   If you operate it they weep, if you ignore it they weep.   Solution is to renew the cork inner seal. 

[Kiwifrog]

If it still has the original style fuel pump they can leak on the connections.

cheers

Alan

[stuart]

Dust talcum powder on the joins as it will show up even the slightest weep. The tank vent down behind the offside rear wheel is a favourite for smells in an enclosed garage too.

Stuart.

[PXC]

Thanks for all these responses - they all need action on my car. 
It has no petrol tap, presumably someone just removed it (because it was leaking???)

it does have the original mechanical pump, but feels and looks dry. 

I reckon the float chamber vents could be the problem, or part of it. They are very short on my carbs, should they have a flexible pipe going down to vent lower down?

That and the cork washers under the jets. 
 

And replace the rubber connections.  

and check the tank vent  

And so it goes on…

[billy l]

The vent pipes should route into the air filters. Cheers, Bill.

[PXC]

Aha! I’ll swing’em round. Thanks Bill. 

[PXC]

Done. 
 

also examined under tank, which looks ok. The tank vent pipe smells strongly of petrol, but then it would do, wouldn’t it. 

[Ralph Whitaker]

11 hours ago, PXC said:

Done. 
 

also examined under tank, which looks ok. The tank vent pipe smells strongly of petrol, but then it would do, wouldn’t it. 

My TR3 stank the garage out with petrol fumes which were entirely from the breather exiting under the car. I crushed the end of the pipe and left the smallest of holes which improved matters. I then noticed that my filler cap has a vent hole anyway, so have now fully closed off the pipe under the car. Next time I take the tank out I am removing the vent pipe completely. Maybe modern fuel is more volatile than the old stuff, or perhaps the original vent pipes had a restriction in them,

Ralph

[PXC]

Good plan. I’ll check the filler cap and close the vent pipe accordingly. 

[TwinCamJohn]

I assume, which is dangerous, that the aftermarket locking cap (Moss) would by it's design not seal completely when closed?

[BlueTR3A-5EKT]

16 minutes ago, TwinCamJohn said:

I assume, which is dangerous, that the aftermarket locking cap (Moss) would by it's design not seal completely when closed?

I would expect the 571086 locking cap to be vented as it was factory specified for all TR models.   They need a filler cap that vents as there is no other vent system other than through the filler cap on later fuel tanks as original.

 

link.  https://www.moss-europe.co.uk/fuel-cap-locking-original-lift-off-round-chrome-571086.html

[PXC]

Mine is not the locking, lift off filler cap. It’s the press-button-spring-open type. I’ll check for vent when the car is back.

thanks 

Paul