Smell of fuel when driving with window open

Hi guys and gals, time to grovel and accept that saying my P38 was ultra reliable was tempting fate. Driving around I've found a really strong smell of fuel building up inside if we've the windows open, back ones in particular. It was so bad yesterday I felt sick. I've crawled under, over, round and round but can't find a leak in petrol or gas systems-with the engine running and warmed up. The only thing I can find is a smell of petrol near the filler cap, which I assume is from the tank vent. Any ideas please?

Close the windows.:rofl:
Sorry that doesn't help you much.
All I can think of is a blocked breather pipe.

I dont know but I suspect the fuel system is a constant loop under pressure hence the hissing when the tank cap is removed if its running rich,or pressure is bieng released during operation fumes will be sucked into the cabin because of the negative pressure
within so close them untill you find the reason. Over here it is mandatory for all fuel to contain 10% ethernol and it stinks, I would not open my windows, but of course the heavac is now working correctly.

Thanks guys, Pete38-where? Breathers I'll clean 'em

Ah-ha, no pressure when I open the petrol cap, that's a petrol leak (or de-pressurisation) somewhere isn't it? Or is it just a symptom of a less than quarter full tank? Am I clutching at straws?

When you are driving is the engine running on Gas? and you still get the smell?
If running on Petrol, is the exhaust system tight? Fumes to cockpit?
You might also try testing the petrol fuel pump pressure, there is a shrader valve on the fuel rail. Pressure should be 2.4 - 2.6 bar (up to 99 model year) 3.5 bar after 99 I believe. This might show a problem with the pressure regulator?
Fuel filter? has it been changed lately?
Obviousley you need to find the leak if there is one and there are loads of places to look, will be most interested to find out what is causing your problem please keep us informed.

Also check the wiring of the gas system as its suposed to stop the petrol injectors working when on gas, are they still working? this might be a red herring as I think it would run horrid? Talking of injectors look for possible leaks on their seals, top and bottom when running fast/slow.

Just had another thought, we had a car in once with bad petrol smell. We got it on the ramp and found a leak from the pipes on top of the petrol pump these are prone to rust, in this case the connector to the return was leaking so the engine ran fine! these connectors are not easy to get to we only found the leak by a drip that was running off the underside of the tank.

Hi Stopover, yes running on gas has the smell, but it's "fuel" cos I can't tell which. There's no signs of a leak that I can find, and I've checked the pipes to the top of the petrol pump, cos that was my thought. The car is running beautifully, which has me thinking about return pipes or breathers. I've got to say that straight after I had the gas conversion done (single point) there was a smell of gas when the tank was full, but that doesn't happen now. I was assured that was a symptom of single point systems because of their crudity-i.e. pump gas into the incoming air supply just before the inlet manifold. I'll keep you all informed as to what's found

If you think the smell could be gas then I suggest you buy a Gas Sniffer, you can usually get them at B&Q or on eBay, Amazon. They are not expensive. When looking they are normally yellow? and battery powered. Go around every part and joint on the gas system including the tank and fittings also the gas filler, and the gas feed pipes. You need to do this cold and during and after running. Also some gas/carbon monoxide detector pads, have them in the car when driving and the gas smiffer switched on to see if gas is the one getting back through the window. If you cant get one try gas detection spray too.
Or get gas system looked at by a specialist.

Try http://www.carbon-monoxide-detectors.co.uk/boats-gas-detectors.htm DB4000 LPG & Natural gas detector pen £44.95 plus p&P might be less in B&Q?

davef2901 said:

Hi Stopover, yes running on gas has the smell, but it's "fuel" cos I can't tell which. There's no signs of a leak that I can find, and I've checked the pipes to the top of the petrol pump, cos that was my thought. The car is running beautifully, which has me thinking about return pipes or breathers. I've got to say that straight after I had the gas conversion done (single point) there was a smell of gas when the tank was full, but that doesn't happen now. I was assured that was a symptom of single point systems because of their crudity-i.e. pump gas into the incoming air supply just before the inlet manifold. I'll keep you all informed as to what's found

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You will know it's a gas leak when it explodes

Datatek said:

You will know it's a gas leak when it explodes

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He could always close the window.

wammers said:

He could always close the window.

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Will that stop the gas exploding:scratching_chin: