Technical B- gassless

[eramosa]

Lately I have been thinking about fixing to get rid of the gas smell in my little B.There is a fuel separator actually in the car. Say it cant be! I let the gas get quite low but according to the gauge there was still gas left. Unh! Unh! After backing her in and out of the garage a few times (working on the house) she refused to start. No Gas.I filled a jerry can and put about 20 liters in but still no go.Tried three or four times waiting each time for the pump to prime.(the same pump I removed last fall to replace the gasket) I expected to spend time this morning drawing gas with a hand vacuum pump.Surprise she started first try. Some times it is just prudent to wait and don't touch anything.

 

[Cribus]

I've been trying to find the source of my fuel smell for weeks, but without success. With the rear bulkhead removed I've been able to look at every part of the system from the fuel cap to the injection rail and there are just no obvious leaks or other places where liquid fuel or vapour are getting out. The smell only happens once I have switched off, left the car and then come back later, it never smells while driving. So I'm thinking it's got to be something to do with the return of fuel from the rail to the tank but all the hoses and connections seem fine (I've replaced the clamps on the hoses where they meet the fuel rail). As I say I've inspected poked and prodded everything that's fuel-related from one end of the system to the other. The charcoal canister system has been disconnected and completely isolated, to remove that from the equation, and the tank breathers now run to atmosphere rather than into the canister so there is no tank pressure build-up (so no hisses when the (new) cap is removed). I've been keeping the fuel level low and that seems to help, but the problem is still there. Anyone have any ideas ? Many thanks !

 

[StevePD]

Hi,
I have the same problem except I have not removed anything from the fuel system, no wet/damp/stained areas of obvious seapage. If I keep no more than half a tank full then I hardly have any smell. So I live with it unless someone has found the secret to stop the problem.

 

[Cribus]

Yes I'm starting to think that I'll just have to live with it. Keeping the tank low isn't the end of the world so there's no point getting fixated about it if I can't find anything to fix.

 

[eramosa]

Did you actually find the fuel vapor separator? I've been so busy with other things I haven't had time to look.It would seem to me that that would be an obvious first place to check. I no of no other car with the fuel vapor separator in the car, but then again the tank is usually outside as well.

 

[Dave-M]

Like so many I had this problem, over the last winter I removed my tank, but before removal I cleaned around the two vent valves and the pump area's, and placed tissue around them, then went for a drive, checked the tissue and found a small leak on the valve nearest the fuel filler. This was a very small leak, had to check 2 or 3 times as it was so small.Did think it was the valve that was leaking ,but I found that the short length of rubber that connect's to pipe (item 5) had deteriorated so replaced this along with all the fixing clips with jubilee clips. So far I have no smell of fuel. So hoping it's cured. As a note the valves are no longer available and no alternative as I can find.

 

[Cribus]

Yes I found it, the separator or segregator (whatever it's called) is to the right of the tank in the rear inner wing with the various pipes running to it. I didn't find any obvious problems with it and I'm not sure what it actually does, the pipes just seem to run through it. But it seemed fine on my car and there was no smell from that area or signs of leaks. That's what's so annoying, I can't pin down the smell to any particular location. Here's a picture of a tank with the segregator attached, on the right. Perhaps someone can say what it does ?...

 

[Cribus]

Ah thanks Dave M, so the segregator gathers fuel vapour from the 2 vents and takes it away, where it ends up in the charcoal canister system at the front. Doesn't handle any liquid fuel. Segregator seemed fine on my car but I'll have another look at the connecting pipe you mention on each of the vents.

 

[StevePD]

Hi,
What happens if you just clamp off the seperator (pipe number 3 on dwg), will it cause fuel starvation or simolar?
Steve

 

[Cribus]

Looks like 3 and 5 take fuel vapour from the two tank vents to the segregator, and 6 then takes the vapour away on the start of its journey to the canister at the front of the car. So I don't think clamping 3 would have any effect, but clamping 3 and 5 would presumably stop the tank venting and cause a vacuum to build as the fuel level drops so something would then follow - fuel starvation ? tank would try to collapse ? both ? But I think there's also some kind of breather or overflow pipe on the left end of the tank that runs in line with the filler pipe, back to the fuel cap area, whether that would allow pressure to escape I don't know...

 

[eramosa]

Dave M, I don't know where you got your exploded diagram from but it's way better than anything I can find here in Ontario. I hope to have some time this week to remove the panel behind the seats and check things out. Last fall when I removed the fuel pump to reseal it it was leaking so bad I figured I had solved the problem.The car was built in June of 97 . With only 21K on the clock and being 18 years old the seal was completely dried out.They don't drive much in Japan. Now I'm just trying to find the correct software to turn off the bloody air bag light.It's Italian,what can I say,we loved our 78 x1/9, and we really like this one. Just have to fix a few bugs.

 

[Dave-M]

Dave M, I don't know where you got your exploded diagram from but it's way better than anything I can find here in Ontario.

It's from Eper, you will find a tab at the top of the Fiat Forum site click on that tab.
Regarding your airbag lights, a tool is availiable, send a private message to Brianpoole, I think he has one, I'm sure he can clarify what you need to buy.

 

[348azeus]

I had this and found it was coming from the seal from the pump/sender unit. Sometimes the unit can actually leak from the multi-plug but in my case it was corrosion on the tank. I couldn't locate a new seal so cleaned everything up and sealed it using Blue Hylomar - make sure its the original as this is impervious to fuel. All back together and its all pleasant.

 

[alcarria]

May be my solution is very obvious.
I had a terrible fuel smell after changing the filling cap. Both caps looked similar, the new one with key and the old one without. After taking a closer look at both caps, I found a small difference in the height of the sidewall, aproximately 1mm more in the new cap. After cutting that milimeter, the fuel smell disapeared.
I hope it helps somebody.