Who out there has had a problem with there C3 far as smelling gas. Is it my hoses or what? Please help! I have a 1976. Have to keep vette out side because of the smelling gas.

 

I have same problem on my '72. I heard it could be the "fuel vapor seperator" located on the top of drivers side of the fuel tank. Anyone have a way of diagnosing if this is the culprit and whats involved to repair? Thx.

 

First thing I'd do is get under the car and check for a leak. Look at the tank/fuel lines along the frame/fuel pump. Look for a wet spots in these areas, you really need to be sure there are no fuel leaks.

 

Replaced this part on my 73. Had gas smell and leaking when full onto muffler due to bubba drilling for luggage rack and drilling hole into the seperator. Not bad to change out if this is the problem. It is a plastic part which might leak or smell if cracked or hoses attached to it are cracked. Two screws holding it onto mount and two hoses attached to it. One to gas tank, and one to fuel vapor cannister under hood on drivers side.

 

Also cars with carburators stink lots more than modern day cars.

 

The more I think about it the more I believe we are stuck with the smell. When I got my Vette, the smell was hard to get used to, never really did. But one thing that used to happen to me was when I would drive the car for any length of time, then stop and say put gas in it, the cap would nearly jump right out of my hands when removing it (sealed cap), so I decided the vapor canister was the culprit, blocked everything off with plugs (the vacuum lines from separator to vapor canister, vapor canister, and carburetor vacuum ports), and put a vented gas cap on the tank. That did not help the situation........few months later, I replaced the separator, the line going to the vapor canister, the vapor canister, and ran the vacuum lines from the canister to the carburetor as designed, and went back to the sealed cap. Well, the cap doesn't jump off the gas tank like before, so am convinced the line from the separator to the vacuum canister is probably plugged. But sadly, after all that, the smell persists. Am going to really check the fuel lines next, and also get a rebuild kit of the QJet. Does anyone know if there is any section of the fuel line that is rubber, or is it all 'hard' lines? thanks. If there is rubber clamped to hard lines someplace, that seems like a good candidate for a leak on a 35 year old car for sure...........

 

I have the same on my 69 big block coupe.

I removed the tank, replaced every rubber line, the gasket on the filler neck, gas cap, changed under hood to all braided steel. I have come to the conclusion that the carb is the only thing left.

Roll up the windows, smell goes away. I'm in the process of making the fiberglass parts to make my L-88 hood functional cowl induction. It won't have a flapper door, functional all the same. See if that helps.

I'm going to go with a FI system when my money tree blooms and produces this fall.

Good luck

 

A carborator has the bowls full of gas when you shut off the engine after you come home. Their is also fuel pressure in the line. The carb may boil over a little or the vapors just come from inside the carb out.

 

My question is, why does this problem exist only on corvettes? I've had Chevelle's Camaro's and others, and have not had this problem. It does however exist on my 70 vette.Considering this, don't see how it can be the carb. Those other vehicles had carbs as well.

 

I only owned vettes so they must just be stinkers.

 

Our 72 or 79 never have a gas smell.

 

You have leak somewhere.

When I first bought my C3 (1980) a couple of years ago I had no problems with gas smell. One day I went out to the garage and had a smell but no leaks on the floor. At first I thought- old car and carburated and I let it go for a couple of days. Finally got fed up with it and after a couple of hours of looking, I found the leak was in my tank on the passenger side. The small leak was dripping on top of the spare tire carrier and drying our before it made it to the floor.

You have a leak somwhere!!

These old cars do smell, but mostly it should be the grease and oils that have accumulated on the underside of the vehicle over the years.

Darrel1

 

My 69 BB coupe has a gasoline smell whenever I have the T-tops in place. It must dissipate when the tops are out, but it can really stink when the cockpit is buttoned up. I replaced the gasket around the locking gas cap and that helped some, but the car still smells like gas when driven closed. Couldn't find any trace of a leak.

 

My 76 smelled of gas when I first got it, mostly due to aftermarket shortcuts and disconnected equipment left by previous owners - unregulated electric fuel pump, disconnected vapor cannister, open fuel pump return line, no pcv. Returning the car to stock configuration eliminated the smells without any reduction in performance that I can tell. Bonus; my fuel economy improved from 9 to 15 mpg...

 

I have a 76 and had the same problem twice. Check hose lines above and behind right rear wheel or fuel pump. I found leaks at different times in these 2 areas. No smell in garage after repair.

 

R44s, on changing the fuel vapor seperator, were you able to source a new one. I heard of guys using epoxy to repair the cracked plastic parts, but buying new would be easier. Any tips on the change out, looks like a tight space needing 1/4 turns with a wrench type of job.

I agree with others there should be no strong gas smell. I've owned other cars from the 60s and 70s, and they never had this kind of smell. If every car in an underground parkade had this smell it would blow up. Gotta be vapour escaping or a leak.

 

I had an awful gas smell from my 72 after driving it and parking it in the garage. I could never find gas leaking on to the floor.It turned out to be a very tiny hole in the rubber fuel return line back by the gas tank.It was dripping on top of the right muffler and evaporating before it hit the ground. Bob

 

Put the car on a hoist and have a very good look under the car.
You have a leak somewhere.

I persisted with the smell for a few months when I first bought my vette 10 years ago, thinking it was just a vapour issue.....

When I removed the spare tyre and tyre cover to investigate better, I found my tank was leaking. No fuel was falling to the ground, as it was caught by the tyre carrier/cover ( I have a 68 )

Exchange rate was pretty bad back then, and a new tank was going to set me back $1200 with shipping and duty to Australlia

I patched the tank as best I could at the time.
Brazed plates over most of the larger holes, but as the walls were very thin I decided to fibreglass the exterior. 2 layers did the trick, and it was good for a total cost < $50

A year ago it began to smell again... tank was leaking once more.
I put a new tank in. No leaking gasoline smells.

 

There is a rubber hose 'jumper' from the [steel] fuel tank feed line to the fuel pump (suction side). If it is an old hose, it can become cracked and have minute weeps that smell but don't drip fuel. If you wrap a tissue around it, some wetness may show up on the tissue. Also, check all of the areas where the two steel lines might rub together and/or rub the frame and wear material off. Eventually, it will wear a very small hole, but the presence of the adjacent line [or the frame] can 'hide' the problem and also minimize the dripping. Finally, make sure that the heat riser/choke system designed for your car is complete and working correctly...or you could be getting carb boil off after shut-down. If engine is modded, this is a bigger issue because no info on how to deal with choke comes with a "pieced-together" induction system.

 

Thanks all for the great suggestions. Looks like a leak hunt is in order. I use to think it was just the carb percolating (stock QJet), but I am now convinced I must have a leak somewheres. Obviously, this has to be a priority repair - gas leak and corvette - not a good combo. Thx again.