Technical petrol leak

[ciccio500]

Hi guys,

Was hoping someone could point me in the direction I need to go. Basically, there is a very strong smell of petrol in my 1970 500L just after you put fuel in, then after leaving it in the garage for the week, come Saturday morning I turn it on to be greeted with the low fuel light!!! So unless someone is taking it joyriding during the week, I think the fuel is leaking from somewhere. Nothing obvious though, I've had a brief look around.

Any help would be greatly appreciated!

Thanks!

 

[fiat500]

Try this link. We went through the issues successfully a few weeks ago. It might also be a loose drain plug which is just visible at the centre of the bottom of the tank at the front. But that's a remote possibility.
https://www.fiatforum.com/showthread.php?t=356694

 

[ciccio500]

Hi all,

So I've looked everywhere and cannot find this leak. It only seems to be happening when the car is parked during the week. I have however noticed that the valve is missing on the fuel cap on the tank so there is just a hole in the top of it.

Could the fuel be slowly evaporating through this? I've phoned a few parts companies and noone seems to have one in stock. Does anyone perhaps know if another classic car uses the same cap that I could buy until I get a proper one from Italy over Christmas?

Thanks all.

 

[Luxe]

My cap has a small hole in the center of it as well and I believe this is normal. Are you seeing leaking fuel? If so you might need to take out the tank and look for a hole underneath.

 

[dk500]

Hi, mine also has a pin hole in top and I had a leaky tank ! Only found pinholes after power hosing inside tank after dropping a bag of fish bowl gravel in ! It cleared inside tank of any rusty grit. Sealed with jbweld. Really cannot believe I could not see the three pin holes prior to hosing out !

 

[ciccio500]

No obvious leak that's what has me stumped. There's no wetness around the tank, and nothing obvious in the engine bay, but half a tank of fuel will disappear off the car is left standing for a week and the garage stinks of petrol. I'm just wondering if the fuel pipe that runs through the car could be causing the issue?

 

[fiat500]

I think the internal pipe might be age-hardened if original but unlikely to leak (unless rubbing on a handbrake cable) except at its unions which are all external and can be easily seen. There will be a length of steel pipe carring petrol through the engine bay which might have turned porous.
It's also possible there is an intenal leak in the fuel pump which would drop fuel into the sump.
Although you've ruled it out, odds are it's the tank...not hard to remove and worth cleaning internally and sealng in any case. case.

 

[Capo]

Ciao, Ciccio!

I'm new here. I got my first 500 half a year ago, a 1970 Giardiniera. The same phenomenon happened to me. It turned out the carb leaked out the fuel. It got a restoration and problem solved.

I hope you'll sort it. It's pretty dangerous with petrol fumes, particularly in my case being an absent minded cigar smoker...

 

[ciccio500]

Ciao Capo,

That's my next port of call.

When I get a day with half decent weather I'm giving the car a proper once over, and the carb will get a thorough service and new gaskets.

I'm going to make a list of everything I need and bulk buy everything from

http://webshop.fiat500126.com

The parts seem great value and less than a tenner to ship to the UK.

Has anyone had experience from this site?

 

[Vitesse]

Yeah I spent over a £1000.00 with them last year. Fred is the main man there and is really helpful. They are very efficient with their deliveries I have ordered parts late on a Friday and they have turned up on the following Monday. They use a courier called DPD that are equally as good as you get a text message that gives an expected delivery time that specifies a particular hour timeframe and they always turn up on time.

Tony

 

[the hobbler]

I too have used Axel Gerstl, and dealt with Fred--have always had 1st class service from them, recommend them.

 

[ciccio500]

Great, thanks guys!

 

[ciccio500]

Sorry to open this up again guys, but just decided to brave a full tank for the first time in a while and whilst I thought the issue was sorted it looks like not!! When stationary, there are a lot of air bubbles coming up the now new see-through fuel pipe from the pump to the carb. Fuel pump is new as is the hose with filter from pump to carb. Any ideas off the top of anybodies head what this could be, or is it normal?

 

[gordinir8]

mine also has bubbles until the line is empty of fuel, bubbles are there also during operation.