Stinking me out of garage, home, & car

[heavy85]

I tried this on the fuel system but no takers so I'll try it here.

 

So I've given up on ever solving the raw fuel smell coming out of the Mikuni's and am moving on to the other source - the arse end. About a year ago I noticed that with 1/2 tank or better I'ld get an overwhelming raw fuel smell. Found the vent lines were bad and replaced them all. Then found the seal under the cap was not sealing so I RTV'ed it and all seemed well. Now, however, what I get is a constant faint ... but annoying ... smell coming from around the filler neck area. It stinks up the garage like there is an open gas can or something and since the garage is below our bedrooms the smell drifts into the house as well. It also stinks up the interior if left with the windows up.

 

There are no visible external leaks and the tank does hold pressure. The fuel system is currently sealed (I'm working on that) and I remove the cap every once in a while to vent it. If it's heated up it will have quite a bit of pressure behind it so I dont think the tank is leaking air but ....... where could this stupid smell be coming from if the entire system is well sealed?

 

I dont want to spend $100 for a filler neck if that wont fix the problem and the fact that it holds pressure and has no external leaks leads me to believe it's OK but on the other hand the smell has to come from somewhere. I would gladly spend the money if I knew it would fix it. Any suggestions on how to troubleshoot this?

 

Thanks

Cameron

[OlderThanMe]

I had the same problem...I one day was getting horrid gas mileage (8mpg) so I opened the hood and discovered that there was gasoline all over my engine bay and was peeling up paint even on the oil filter. It turned out that my mechanical fuel pump diaphragm had cracked. Since then there has been no smell at all. I also had my gas tank acid dipped and recoated at a local radiator shop for $120.

[bjhines]

There are vent lines to and from the vapor tank on the passenger side rear quarter....

 

one of those lines runs though the rear frame rail and is a bugger to get through the hole... I used a string with a shop vac to get a "pull line" through and then used that to pull the new line in place.

[heavy85]

All those vapor lines were replaced and there is no visible wet spots even after hard driving ... plus I dont have a mechanical fuel pump. It's definitely coming from around the filler neck / vapor tank area. Any other ideas?

 

Thanks

Cameron

[OlderThanMe]

yep...the clamp where the rubber filler neck clamps onto the metal tube may be loose or be dirty. On my Z there are like 7 lines coming out of the tank and are a pain to hookup with a small clamp. Mine pulled out once and so when I filled up with gas it overflowed onto the ground.

[JMortensen]

All those vapor lines were replaced and there is no visible wet spots even after hard driving ... plus I dont have a mechanical fuel pump. It's definitely coming from around the filler neck / vapor tank area. Any other ideas?

 

Thanks

Cameron

A new filler neck is SOFT plastic. After just a few years exposure to gas fumes they become hard as a rock. When I replaced mine about 8 years ago, I literally had to chisel the flange of the old one off in the gas tank compartment to get it out. When they get that hard they can crack, and it's also harder for the tube to make a good seal on the tank. There is a plastic connector for the vapor hose that connects to the filler tank. It also is very likely to get hard and crack. I'd look for cracked hoses and bad connections that won't tighten up.