kbrin

Hi, My C3 has the stock edel manifold and a holly performance carb.
I am getting the smell of gas in the cockpit and can find no leaks in engine compartment. the car runs a little rough at idle but never quit s and runs perfect at speed. the smell comes and goes and I am trying to figuire out what I am doing at the time I smell it.
Any advice is appreciated.
Love my C3!
Kevin

bobs77vet

kevin do you park inside? if so do you smell gas fumes in the garage? take a flashlight when it gets dark and look around the right hand side of the gas tank thats where the fuel line coming out and returning goes into the gas tank, its not unusal for the return line to leak when it gets old. to fix it you have to drop the tank. open the gas lid and look around the top of the tank for wet spots

let me see if i have a picture

look at the bottom of the hose my finger is holding up right in line with the edge of the lower hose you can see the tear

dochorsepower

Also check the small connector hose at the fuel pump. Your fuel smell could just be a bad hook-up at the vapor cannister, but any fuel smell is bad. Find it before it finds you.

kbrin

Thanks, i will check this out. i do garage it but it never get the smell unless its running---But not all thetime? still playing around to see what I am doing when i get the smell. cruising on the freeway is no probem even with air on or off, vents open or losed.

kbrin

Thanks I will check this out also.
Kevin

gq82

If you have a 70>74 there is what's called a Gas Tank Vapor Separator attached to the gas tank. This allows gas vapor to travel to the carbon canister in the engine compartment but prevents raw gas from doing the same. These and their associated hoses over time tend to leak when the tank is full or nearly full and the gas is sloshed around. You can see it on the left side of the gas tank. This was the cause of my gas smell many years ago. You can buy them at Zip.

http://www.zip-corvette.com/ProductD...GR-SR&CTitle=&

kbrin

Thanks. i have an 81 c3, do i have the same vapor separator?
Can i find it in the same place, orany other ideas??
Thanks much

kbrin

I am almost convinced the vapor is from the vacuum somewhere. Do I need the canister hooked inline or can i bypass it altogether. do I also need the return side? or can i just use fuel supply.
The only thing that seems constant is than when I make a turn the vapor returns for a brief moment.

ignatz

I just went through fault isolation on this because of a recurring fuel smell. My car however went through a complete teardown and rebuild whereas yours has been in use so none of this may apply. But something here might be relevant.

My leak occurred because when I rebuilt the car I reused my filler neck which had a distorted mounting flange from a couple of on and off and maybe too tight cycles. It didn't sit flat on the tank proper and the gasket couldn't accommodate the distortion. So when the tank was near full the fuel sloshed around under the rubber catchall and passed by the gasket. Impossible to see.

I found it by removing the spare tire carrier and looking up at the tank with a flashlight and mirror to where a residue trail had built up. Since your filler neck hasn't been on and off (I presume) this leaves the gasket as a possible. Anyway, it was off to the store to pick up a brand new part. OK, right? Well no. It was the same sloshing around story but now I could see the fuel in the rubber catchall cup.

Turned out the top of the brand new shiny filler neck wasn't flat and there wasn't enough sheet metal to sand it flat. Quick visual was to put it on my table saw and shine a flashlight inside. Plenty of light seeping from the table saw flat.

Solution was the store had an old original neck flat on both ends. Now no leaks. This may not help you, it is more likely an old hose, but at least I feel better not breathing fumes. And if anyone reading this buys a new neck, check the top for flatness.

kbrin

Thanks for the info.
This actually makes a lot of sense since the smell is very strong at the gas fill area. I pulled back the rubber catch all and was surprised how heavy it was in inside. the tank and neck has never been removed to my knowledge but a new gasket can never hurt. I planned a complete hose restore but this will be the icing on the cake.

FYI i also think i need a carb rebuild or i may even buy new.
I have the edelbrock mani and a Holly performer carb. I think these were replaced