Fairly constant fuel odor

[Andrew.Bertschi]

My ex-NZ 1978 Mini 1000 has a fairly constant fuel odor outside the car that is noticeable when you stand within 5 or so feet of the tank area. There is no smell inside the car or the boot area and the odor is not dependent on fuel level or type. My car has the small 5.5 imp gallon tank and a vented locking cap like in the photo.



I took the tank out recently for other reasons and checked and cleaned it - all looked good including with the factory vent line and metal fitting at the top of the tank. All the rubber hose sections on the car were replaced prior to going to Bend. The car has a mechanical fuel pump and a thorough visual inspection underneath showed no leaks of any kind. I suspect the cap may be the issue here as it seems to fit slightly 'loose' on the stem, at least in relation to other older cars that I have owned. That being said, the rubber seal on the cap looks fine and the cap itself appears 'near-new' with no obvious damage.

My questions are:

- Since the car has a built-in tank vent system, would it have been fitted with a vented or a non-vented gas cap from new?
- Besides the cap, what other reasons that I cannot think of could cause the fuel odor?

Thanks,
Andrew

[innochadi]

Hi Andrew, just saw your post from a month ago. Did you ever get this fuel odor problem resolved? I had the same issue a couple years ago (worse actually; mine leaked bad, too) and went through 3 or 4 different styles of vented caps before I found one that sealed well to my filler neck. Maybe try some other caps to see if one works better for you than what you have.

[Andrew.Bertschi]

Hi Chad,

I'm pretty sure the issue is fuel cap related. My car is supposed to have a non-vented cap but currently has a vented one. I've ordered the correct cap and once it arrives, am very curious if that will resolve this issue? I tend to think it will.

[Andrew.Bertschi]

Update

I recently bought a new, non-vented fuel cap and installing that seems to have solved the issue.