Gas odor after running
Thread Starter
Intermediate
Joined: Jul 2004
Posts: 28
Likes: 0
From: New Castle PA
Gas odor after running
Started car in garage and idled for about 20 minutes. Shut off and within about half hour of garage door being closed strong smell of gasoline. No leaks visable anywhere on the floor. Smells like coming from under hood around Carb. Any ideas if it could be Carb or a vacum line?? Thanks for the help!
Racer
Joined: Mar 2002
Posts: 406
Likes: 1
From: Maroochydore QLD
I can think of two obvious causes, both pretty common when over 30 years old.
1. vapour canister needs replacing or vacuum lines are broken, removed or disturbed to this system.
2. If it is an original Rochester carb, they often leak fuel from the bowl after you turn the ignition off due to missing or shrunk lead plugs. One symptom of this is that you may have to crank your engine for a good 10 seconds or so first thing in the morning before the fuel pump sends enough fuel to the carb to start the engine.
See how you go with those two suggetsions.
Dennis.
1. vapour canister needs replacing or vacuum lines are broken, removed or disturbed to this system.
2. If it is an original Rochester carb, they often leak fuel from the bowl after you turn the ignition off due to missing or shrunk lead plugs. One symptom of this is that you may have to crank your engine for a good 10 seconds or so first thing in the morning before the fuel pump sends enough fuel to the carb to start the engine.
See how you go with those two suggetsions.
Dennis.
Intermediate
Joined: Jan 2010
Posts: 33
Likes: 0
From: Redondo Beach California
Mine smells like fuel all the time. No leaking gas, less then 4000 miles since rebuild. But on the other hand, morning starts usually take a few seconds. In the afternoon she fires right up.
Burning Brakes
Joined: Jul 2009
Posts: 1,240
Likes: 294
From: ESCONDIDO CA
2025 C2 of the Year ('63 and '67) Finalist - Unmodified
C2 of Year Finalist (appearance mods) 2019
I love that smell. After a 20 minute jaunt, even my clothes have that wonderful odor of octane.......sweet!
Burning Brakes
Joined: May 2006
Posts: 774
Likes: 1
From: Round Rock Texas
man, this post was a jinx. I gave my humble opinion and went out to the garage and noticed a puddle on my floor. Fuel pump was leaking (Edelbrock). I tightened everything, but it is still weeping a little. AHHHH!!!
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Team Owner
Joined: Jul 2008
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From: In limbo
St. Jude Donor '13-'15, '17 thru '22
Mine stunk up the garage after running when I bought it. So many people said the same thing, I was wondering if it was normal, but I never noticed it with my old car (sold in 1995). I looked for a fuel leak for months, and never found anything. Then, my carb took a dive, and when I replaced it, no more stink. I definitely had a fuel leak at the carb that I fixed when I replaced it. Now, after a drive, when I walk into the garage to cover the car, I can get a little whiff of gas, but it doesn't stink up the garage or anything. Also, I have let the car sit for a month, and there is still gas in the bowls of the carb, so I am pretty sure she isn't leaking any more fuel now.
Drifting
Joined: Aug 1999
Posts: 1,468
Likes: 1
From: Kirkland WA
It's not "normal" to smell like gas. Normal would be what they did originally, and originally they did not smell of gas.
If you have a gas smell, something is wrong. Most likely causes (that are less obvious then the typical problems like leaking fittings), based on what I've seen:
- Old rubber fuel lines. Newer gas blends can wreak havoc on some brands of rubber and cause them to soften. Right after you drive, run your hands on both ends of all rubber lines. Any wetness at all is a problem.
- Carb is boiling over/bad epoxy on the well plugs
- Bad seal around your sending unit. I had this exact problem I chased forever. The original rubber seal for the sending unit was weeping EVER so slightly and causing a terrible stink. Just beacuse it smells like it's coming from the engine - check up near your gas tank if you've confirmed no problem with anything above.
If you have a gas smell, something is wrong. Most likely causes (that are less obvious then the typical problems like leaking fittings), based on what I've seen:
- Old rubber fuel lines. Newer gas blends can wreak havoc on some brands of rubber and cause them to soften. Right after you drive, run your hands on both ends of all rubber lines. Any wetness at all is a problem.
- Carb is boiling over/bad epoxy on the well plugs
- Bad seal around your sending unit. I had this exact problem I chased forever. The original rubber seal for the sending unit was weeping EVER so slightly and causing a terrible stink. Just beacuse it smells like it's coming from the engine - check up near your gas tank if you've confirmed no problem with anything above.
Burning Brakes
Joined: May 2006
Posts: 774
Likes: 1
From: Round Rock Texas
Also, it may be running too rich and leaves a heavy odor. But, small smell is what you get. Even my 02 Z06 had a small gas smell in the garage and it had nothing wrong with it. A gas engine is going to leave some odor residue, but I love the smell my car leaves on me when I get back from terrorizing downtown.
Race Director
Joined: May 2007
Posts: 11,334
Likes: 136
From: Out of Site...Out of Mind. Corvette: anything else is just transportation.
St. Jude Donor '09 thru '20
I can think of two obvious causes, both pretty common when over 30 years old.
1. vapour canister needs replacing or vacuum lines are broken, removed or disturbed to this system.
2. If it is an original Rochester carb, they often leak fuel from the bowl after you turn the ignition off due to missing or shrunk lead plugs. One symptom of this is that you may have to crank your engine for a good 10 seconds or so first thing in the morning before the fuel pump sends enough fuel to the carb to start the engine.
See how you go with those two suggetsions.
Dennis.
1. vapour canister needs replacing or vacuum lines are broken, removed or disturbed to this system.
2. If it is an original Rochester carb, they often leak fuel from the bowl after you turn the ignition off due to missing or shrunk lead plugs. One symptom of this is that you may have to crank your engine for a good 10 seconds or so first thing in the morning before the fuel pump sends enough fuel to the carb to start the engine.
See how you go with those two suggetsions.
Dennis.
Had the same problem a couple of months ago with my vapor canister.
Good luck, normally it's not just one thing. I replaced the canister and got rid of most of the smell, not all. I'll be running down the fuel/vapor lines next.
