Fuel smell persists
Thread Starter
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Fuel smell persists
Just p/u the car from the Vette shop. They pulled the gas tank, checked all hoses back there and found them OK. While it was out, I had them pull the bladder out of the tank so that I could get a full tank of fuel for the first time.
Steel fuel line to front of car is fine. Rubber hoses at pump and fuel pump are both new. Rubber lines to vapor cannister are good and dry. No puddles under the cannister so I doubt it's full of gas.
Carb just gone thru by Lars.
So what the hell is making it stink up the garage? It stinks so badly when sitting in traffic, that you think you're sitting on a bomb. I'm getting concerned now! I've had six sets of eyes on the problem, and nobody can see a leak. I paid to have the tank pulled because I didn't wanna mess with it myself - but I fully expected them to find rotten hoses back there.
On the way home I was finally able to get a full tank of gas in the car though ... it took 16 gallons to fill which is four more than I've EVER been able to squeeze in.
Steel fuel line to front of car is fine. Rubber hoses at pump and fuel pump are both new. Rubber lines to vapor cannister are good and dry. No puddles under the cannister so I doubt it's full of gas.
Carb just gone thru by Lars.
So what the hell is making it stink up the garage? It stinks so badly when sitting in traffic, that you think you're sitting on a bomb. I'm getting concerned now! I've had six sets of eyes on the problem, and nobody can see a leak. I paid to have the tank pulled because I didn't wanna mess with it myself - but I fully expected them to find rotten hoses back there.
On the way home I was finally able to get a full tank of gas in the car though ... it took 16 gallons to fill which is four more than I've EVER been able to squeeze in.
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
Get down real closely by the carb and check. If you can't see clearly, use a match... 
Actually, is there a dye you can use to put in your tank then look for color? They use something like this for AC leaks. Maybe there's one that lights up under UV like when they look for DNA evidence on CSI???
Actually, is there a dye you can use to put in your tank then look for color? They use something like this for AC leaks. Maybe there's one that lights up under UV like when they look for DNA evidence on CSI???
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Try the dye...1 ounce bottle to 1/4 tank......AutoZone has the dye and the U-V lamp, about 60 bucks...a cool tool for the tool-box
P.S....check the steel lines from the tank to the engine, along the frame rail
P.S....check the steel lines from the tank to the engine, along the frame rail
Burning Brakes
Joined: Mar 1999
Posts: 1,047
Likes: 3
From: CA
I just did a quick search on Google and it appears there are a number of gasoline detectors similar in style to a freon detector. They are not cheap, but it may be worth the investment to trace down where the fumes are coming from.
Instructor
Joined: Nov 2001
Posts: 175
Likes: 0
From: St Louis MO
If you have the steel line that runs up the front of the engine from the pump to the carb it may be leaking. I have seen worn spots where it passes through the a/c compressor bracket. Also check that your fuel cap is seating properly otherwise it will allow fumes to escape and will stink.
Thread Starter
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by Techno
Longshot- could it be running so rich that its the exhaust your smelling?
The smell of raw fuel is unmistakeable. But thanks for the thought I wish that was the case. I've built motors and driven hot rods all my life, so I know it's not that.
Thread Starter
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by yogi78
If you have the steel line that runs up the front of the engine from the pump to the carb it may be leaking. I have seen worn spots where it passes through the a/c compressor bracket. Also check that your fuel cap is seating properly otherwise it will allow fumes to escape and will stink.
While in the air, the steel line along the frame was checked out, along with all the rubber ones and found to be just fine. In fact they remarked how GOOD everthing DID look. They actually remarked at the Vette shop, that my 60K odometer on the car is probably actual, and not rolled over as one would expect on a '76.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Originally Posted by SanDiegoPaul
Now there's a couple of interesting thoughts. The gas cap is a locking one that was on the car when I bought it, dont' know how old it is. It appears to be working well and I can hear pressure dissapate when I open the tank. Guess that means it's sealing OK. I have routed the steel pressure line myself, around obstacles but it may be worth another check.
While in the air, the steel line along the frame was checked out, along with all the rubber ones and found to be just fine. In fact they remarked how GOOD everthing DID look. They actually remarked at the Vette shop, that my 60K odometer on the car is probably actual, and not rolled over as one would expect on a '76.
While in the air, the steel line along the frame was checked out, along with all the rubber ones and found to be just fine. In fact they remarked how GOOD everthing DID look. They actually remarked at the Vette shop, that my 60K odometer on the car is probably actual, and not rolled over as one would expect on a '76.
Thought the latter year C3's had self venting caps so there should be no vaccum (think that you are hearing air rush into the tank not out) built up in the tank? Believe the eng is supposed to suck the fumes out of the tank and the vented cap allows there to be no vaccum build up. Not sure it is related to your probelm or not but thought I would mention it.
Team Owner
Joined: Apr 2002
Posts: 25,778
Likes: 0
From: Zionsville, PA NRA Life Member
St. Jude '03-'04-'05-'06-'07-'08-'09-'10
I was reading my new issue of Corvette Fever ( sept '05 ) during lunch just a few minutes ago. In the "Shark Attack Part 10 " article , on page 66 they talk about the fuel system vapor canister.
Here's the paragraph that might help you out.
Hope this helps you out 
Jeff
Here's the paragraph that might help you out.
Originally Posted by Corvette Fever Magazine,Sept'05 issue, page 66
The last item to replace is the fuel system canister tucked away in the driver-side inner fender. The fuel system canister is often overlooked and should be replaced every 10 years. The fuel system canister stores fuel vapors that build up in the fuel tank. In today's world, that means better fuel mileage. Ever wonder why you might have smelled a fuel odor at the driver's side fender? The original hoses deteriorate over time, with the charcoal in the canister eventually crumbling into dust,limiting its ability to store vapors. This causes fuel odors. We make the canister operable on all cars, whether fuel-injected or carburated.
Jeff
Thread Starter
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by Solid LT1
One far out in left field but, is your fuel pump leaking into the crankcase? I have seen this problem before, or Carb float level problems on you motor.
Float level is correct ...
Safety Car
Joined: Jun 2002
Posts: 4,135
Likes: 1
what about the fuel vapor seperator pictured below, they are glued at the top and the glue lets go after 30+ years,,, i poped off the top and inside is a ping pong ball and a needle/seat,,i re-glued the top on and painted it black,,,problem went away------------by the way the part is no longer available except thru salvage,,i bought a spare and re-glued the top also...got it from corvette mike for $50.00 its located on the drivers side of gas tank at the top. and if the gas cap is non-vented,,, pressure builds up and the vapor separotor leaks at the glueline............
Melting Slicks
Joined: Aug 1999
Posts: 3,123
Likes: 13
From: Hollywood, Florida
The canister holds VAPOR, not fuel;Therefore, you wouldn't have a puddle of gas there but it still could be shot.
If the charcoal is 10+ years old, it has done it's job and the canister needs to be replaced. ALL fuel smells went away after I replaced mine a couple of years ago after verifing the lines/hoses/fittings were sound.
If the charcoal is 10+ years old, it has done it's job and the canister needs to be replaced. ALL fuel smells went away after I replaced mine a couple of years ago after verifing the lines/hoses/fittings were sound.
Safety Car
Joined: Jun 2002
Posts: 4,135
Likes: 1
Originally Posted by shoptek
The canister holds VAPOR, not fuel;Therefore, you wouldn't have a puddle of gas there but it still could be shot.
If the charcoal is 10+ years old, it has done it's job and the canister needs to be replaced. ALL fuel smells went away after I replaced mine a couple of years ago after verifing the lines/hoses/fittings were sound.
If the charcoal is 10+ years old, it has done it's job and the canister needs to be replaced. ALL fuel smells went away after I replaced mine a couple of years ago after verifing the lines/hoses/fittings were sound.
Melting Slicks
Joined: Aug 1999
Posts: 3,123
Likes: 13
From: Hollywood, Florida
Originally Posted by carl a
when my fuel vapor seperator went. every time i filled the tank i had raw gasoline dripping on my chambered exhaust system in the area of the drivers side rear wheel,directly below the fuel vapor seperator- gas was leaking from the top glued cap of the seperator i posted above, re-glueing it stopped the problem,not that this defenetly is his problem,but could be
Le Mans Master
Joined: Mar 2000
Posts: 9,127
Likes: 2,326
From: Pottsville, PA. USA Home Of America's Oldest Brewery Yuengling
1974 is the last year to use the fuel vapor seperator. The canister in the left front fender has a filter in the bottom of it. I replaced the filter in my car along with all the hoses from the canister. Dr Rebuild sell a kit with the correct hoses and clamps.
Safety Car
Joined: Jun 2002
Posts: 4,135
Likes: 1
Originally Posted by shoptek
You are 100% correct. If the F/V seperator that mounts to the upper left side of the fuel tank splits, it WILL leak raw fuel, but the evaporative canister, in the left front fenderwell goes, it will usually not leak, but will stink of raw fuel from being logged with gas vapors.
Melting Slicks
Joined: Aug 1999
Posts: 3,123
Likes: 13
From: Hollywood, Florida
Originally Posted by carl a
i should get around to replacing that charcoal cannaster filter,was it expensive?(probably is! what isnt on our cars!!) and was it e/z to replace??
I took mine out thru the left side vent after I removed the eggcrate grill. As I recall there are 4 bolts that hold the mounting bracket. You remove the bolts from the fenderwell area.
If you replace the rubber hoses, one of them have a very small restrictor that slips in the hose. Make sure you remove it befor yo toss the old hoses.