My '73 Mini has developed a strong gasoline smell. I cannot find any leak on the garage floor. It is strongest near the fuel tank and near the hood. There is no odor in the trunk and very little under the hood.

I'm traveling right now but I plan to drain the tank. I have heard that the mechanical fuel pump can fail at the diaphragm and leak fuel into the crankcase so I intend to have a look at the oil when I get back.

Any more ideas?

 

Are you sure the fuel is not leaking out of the cap and running down the side? This was common on the earlier 60's vintage Minis.

 

Non Mini experience, but I had a Nissan Max once that had a fuel leak on the injector fuel rail. It does not take much of a leak to produce a strong smell. So you may not see or need to see a puddle. Could only be visible as a wet spot on a fuel line, hose, etc.

 

I had the same thing happen to me on a 93 Jeep Cherokee. The smell was coming into the cabin through the vents so it was hard to identify the source at first.

 

No leak from the from the gas cap. Had that happen already and replaced it. Made a mess on the car!

I agree that it doesn't take much fuel to stink, but boy does it stink.

 

Check your flex hoses and pump for leaks. Also check your SU float bowl lid gasket and make sure it is not overflowing due to a dirty needle valve or misadjusted float. Sometimes they crack & fill with gas, too.

 

When my mech pump leaked the entire garage reaked of gas, but no puddles. The warm engine would cook off the gas which seeped until the pressure bled off. I could only see the leak when the engine was running and then was wondering how long it had been like that....

I've a spare in the box mechanical pump if interested. (Don't ask why I bought two) .... or you can blank off the attachment point and go electric.

 

Fuel hoses look good. Now that you mention it, the top of the fuel pump had a layer of damp crud on it (but no obvious dripping) that I noticed while checking the hoses and carb float chamber. What's the story on spacers for the mechanical pumps?

 

Have you checked the small breather pipe to the top of the fuel tank inside the boot (sorry trunk!) has not come off (only a push fit) and is also venting through the boot floor? It is also clipped to the rear bulkhead.That fixed it for me once, although you did say there is no smell in trunk.

 

I did see the bottom end of breather pipe but I haven't verified that it is still connected to the tank...

 

The story on the spacer????

The spacer only holds the pump off the block and keeps the 'pressure' in....

When I bought a new mech pump I ordered a new spacer....it is still on backorder.....3 years! But it is just a block of rubber with no fluid involved so I appear to be OK

The layer of damp crud on the top of the pump sounds very familiar. I kept thinging bad hose or loose connection and replaced everything 'til I finally accepted that the pump was leaking around the edge... new pump, pob' gone.

Altho I'll note that getting the mounting bolts out on my 1275 was a ***** ... no space to work.... I bought three new tools b4 I got it done. An 11mm ratcheting wrench ended up being the winner!

And b4 anyone else says it - yes, you can blank off the mechanical's mounting point and go electric.....I'm trying to stay one side of the line of 'original' and see this as the other side...today, anyway

 

I'd rather stay with the mechanical pump meself. I have experience with SU electric fuel pumps on my MGB. Yep, it looks like the fuel pump is gonna be fun to get at...

 

It can't be any worse than the speedo cable. ... Can it??

 

I had a leak at the gas gauge sending unit on my tank. Had to reseal it and all was good.

 

For the mechanical fuel pump, its easier to pull the manifolds, and clean the backside of the engine compartment while your in there. If you have tappet covers, replace the gaskets there, too.

 

Got in last night and clamped off the suction hose on the fuel pump. According to Haynes if the tank is more than half full it will fill the fuel line up to the pump. After wiping the pump body down with some degreaser the smell subsided. There was very little "wet" on the pump but apparently it was enough to stink up the garage.