Strong fuel odor
Thread Starter
Cruising
Joined: Feb 2024
Posts: 14
Likes: 0
Strong fuel odor
Help!! Working on my 1981 C3. Previous owner(s) have done many modifications including removal of the air pump and catalytic convertor. Sloppy workmanship with electrical splices connected with wire nuts! A couple of weeks ago the car began running rough. When shut off you could see fuel continuing to flow through the glass fuel filter and fuel dripping in the carb (Edelbrock 1407). I rebuilt the carb last weekend; the floats were out of adjustment by a mile. The engine started well but still surged from 700 to 1100 at idle; the idle mixture screws seemed to have no impact.
Now there is a very strong fuel odor from the car, even when it sat without being driven for a couple of days. No fuel puddle visible under it but I backed it out of the garage because the woman of the house says it is making the interior of her car smell like gas. So, where do I start? Rebuilding the carb had little impact so now I need to know where to begin searching for the source. No visible leak in the fuel tank area.
Now there is a very strong fuel odor from the car, even when it sat without being driven for a couple of days. No fuel puddle visible under it but I backed it out of the garage because the woman of the house says it is making the interior of her car smell like gas. So, where do I start? Rebuilding the carb had little impact so now I need to know where to begin searching for the source. No visible leak in the fuel tank area.
Safety Car
Joined: Nov 2002
Posts: 4,179
Likes: 1,174
From: out of nowhere
I am not familiar with the 1982’s, but if they are anything like earlier C3’s there could be a vapor collection system, with a line going from the tank to a canister of charcoal. That line could be dry rotted and cracked or the charcoal canister might be beyond capacity. It may also have been removed and rubber nipples plugged the outlet at the tank. I would check all of those rubber lines as well as any rubber nipples. Also check the rubber seal around your gas cap. The previous owner may also have put in a fuel pump that is putting out pressure greater than what your carb needs. I recently started reading up that guys will install pressure regulators for this reason. All of that smell could also be coming from all of that extra fuel you said you are seeing going into the carb after shut down. Just thinking out loud on what I would check, but there are smarter folks than me here, so hopefully you can get some gooder input than those ideas. Hope you can get it sorted either way.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,008
Likes: 4,166
From: US-PNW
Do you have any idea what kind of fuel pump you have? That it still pushes fuel after shut-down sounds like it's putting out excessive pressure or something... I believe most recommendations are for ~5-6 psi when running.
A few minutes after shutting it down, how does the engine restart and run?
A few minutes after shutting it down, how does the engine restart and run?
Thread Starter
Cruising
Joined: Feb 2024
Posts: 14
Likes: 0
Do you have any idea what kind of fuel pump you have? That it still pushes fuel after shut-down sounds like it's putting out excessive pressure or something... I believe most recommendations are for ~5-6 psi when running.
A few minutes after shutting it down, how does the engine restart and run?
A few minutes after shutting it down, how does the engine restart and run?
Thread Starter
Cruising
Joined: Feb 2024
Posts: 14
Likes: 0
Wow, thanks 67:72!! Good info I didn't have. I will find a pressure regulator with gauge and experiment with the setting at around 6 psi.
The charcoal canister is in place with hoses attached; however 3 of the hoses are hanging loose going nowhere. I have a chart showing the hose routing but some of the items the hoses are supposed to connect to are absent, the "purge TVS" being one. The air cleaner was also replaced with an Edelbrock version. It has a connection for one of the hoses...just have to figure out which one. Chevrolet managed to find an interesting location for the canister.
The charcoal canister is in place with hoses attached; however 3 of the hoses are hanging loose going nowhere. I have a chart showing the hose routing but some of the items the hoses are supposed to connect to are absent, the "purge TVS" being one. The air cleaner was also replaced with an Edelbrock version. It has a connection for one of the hoses...just have to figure out which one. Chevrolet managed to find an interesting location for the canister.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski