evaporative control canister
Safety Car
Joined: Jun 2004
Posts: 4,652
Likes: 80
From: Lakeland Florida
....... I am going to remove the spare tire and try to feel if the fuel separator valve is still snug in place on the drivers side top of the gas tank; if I can reach it, I will order a replacement just to be sure. If this does not work, I will buy some hose and hook the canister back up and run this hose back to the tank (this will test weather the original vapor line is plugged or not). ....................In the meantime, will leave the garage door cracked open. 
Can you update what you found out with this. Were you able to get to the fuel tank separator valve and replace the hoses. That is something on my list but it looks like you have to drop the tank to get to this.
kdf
Melting Slicks
Joined: Sep 2006
Posts: 2,810
Likes: 469
From: Wichita Kansas
Good Timing. Just last night I replaced the fuel separator finally, the hoses looked in great shape. I drove it for about 30 minutes afterwards and this morning (Tuesday), I fear the smell remains. So I am going to the store on the way home and buy a bunch of hose to go from the separator to the canister to see if that cures it (that might indicate that the steel line is plugged). After that I will repost results. I can think of no other solution than to question where I have the hoses going from the canister to the carb. But they are hooked up per the AIM so............
Safety Car
Joined: Jun 2004
Posts: 4,652
Likes: 80
From: Lakeland Florida
I was asking becasue I had an issue on this last night. I searched the forum and found this thread.
I parked my 75 in the garage, and went upstairs. It is a 2 story house, and the kitchen is over the garage. I went to my room changed my clothes, and watched maybe 15 minutes of TV. I came back out to the kitchen and it smelled like I poured gas all over the floor. I ran around and opened every window in the house the stench was so strong.
Went down stairs, opened the garage door and pointed the fan towards the car to drive out the smell. I checked the car and did not find any wet spots anywhere. Last night was the worst that it has ever been.
I figure I will not drive it until I have time to crawl under neath and replace the cannister lines, and the fuel pump vapor return line.
kdf
I parked my 75 in the garage, and went upstairs. It is a 2 story house, and the kitchen is over the garage. I went to my room changed my clothes, and watched maybe 15 minutes of TV. I came back out to the kitchen and it smelled like I poured gas all over the floor. I ran around and opened every window in the house the stench was so strong.
Went down stairs, opened the garage door and pointed the fan towards the car to drive out the smell. I checked the car and did not find any wet spots anywhere. Last night was the worst that it has ever been.
I figure I will not drive it until I have time to crawl under neath and replace the cannister lines, and the fuel pump vapor return line.
kdf
Le Mans Master
Joined: Jan 2003
Posts: 6,575
Likes: 1
From: Tuttle OK
Cruise-In VIII Veteran
Melting Slicks
Joined: Sep 2006
Posts: 2,810
Likes: 469
From: Wichita Kansas
I have had it now...........
I am so effin fed up with this. I have done all I could to return this stupid system to service: New canister, new rubber throughout, new fuel separator, new sealed gas cap. The gas smell is just as effin bad as it was. I don't have hi perf engine so the two hoses going into the carb are going into the front; that is all there is on a 72. I guess I will pull those one at a time and see if the carb is pulling vacuum thru the two ports; I might even try to hook those to the passenger side of the carb where the hi perf shows they go. After that fails I'm afraid I will just blow up, oh I just can't stand this, dammit GM can just stick this whole thing up where the sun don't shine and turn it.
GM can just stick this whole thing up where the sun don't shine and turn it.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
My C3 stunk up the garage for 10 years before I finally figured it out. The tank had rusted through between one strap and the tank (underneath the strap). It only smelled (leaked) when it was near a full tank of gas..... because that was the height of the pin-hole leak. It was leaking just enougn to smell, but not enough to see any evidence. Probably not your problem, but noteworthy.
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
If you have all the evap parts working and still getting a smell that bad, I would bet on a carb leak somewhere. The canister can only do so much and only with the devices its connected to.
The system on my 81 has a lot more hoses on it than the 72 does, if you have a diagram you can send me I'll see if I can figure out how it works and maybe I can help.
The system on my 81 has a lot more hoses on it than the 72 does, if you have a diagram you can send me I'll see if I can figure out how it works and maybe I can help.
Intermediate
Joined: Nov 2005
Posts: 47
Likes: 0
From: Colorado Springs CO
I know your frustration gentleman. I had a bad gas smell also. When I restored the car I focused on all of the following things. Here is what I did and it eliminated the gas smell.
New Edelbrock Carburetor (JET performance calibrated)
I sealed the tank gas tank sealant with POR sealer.
New lines, hoses, separator, etc., rebuilt the canister, new hoses from carb to canister.
Make sure that the lines are hooked up correctly from the separator to the tank and the ECC. Easy to turn them around. If these are wrong you will have fuel going straight down the line to the ECC. Don't ask me how I know.
Here's a picture of my lines on a 71 BB.
New Edelbrock Carburetor (JET performance calibrated)
I sealed the tank gas tank sealant with POR sealer.
New lines, hoses, separator, etc., rebuilt the canister, new hoses from carb to canister.
Make sure that the lines are hooked up correctly from the separator to the tank and the ECC. Easy to turn them around. If these are wrong you will have fuel going straight down the line to the ECC. Don't ask me how I know.
Here's a picture of my lines on a 71 BB.
Melting Slicks
Joined: Sep 2006
Posts: 2,810
Likes: 469
From: Wichita Kansas
Don't know if you will read this update, but few weeks ago I arranged to replace the fuel separator, and then bought and ran a length of rubber hose from the separator to the vapor canister, completely bypassing the hard line. Well, the good news is that even with the proper sealed gas cap, the gas tank is not building up lot's of pressure after a drive as it was before. The bad news is, the gas smell remains. I have the spare tire carrier out and there are not leaks from the tank and the rubber hoses are all supple and intact. I guess maybe the carb needs an overhaul, have heard about gas continuing to enter the carb bowl after the engine is shut off. Or maybe a new fuel pump,,,,,or both.
Instructor
Joined: Dec 2001
Posts: 101
Likes: 0
From: Manitouwadge Ontario
Vented gas cap - where can I order one from?
I have a problem where my secondary boosters are leaking. From the notes above I'll try a new gas cap to see if it helps. Where are these being ordered from. I have a 74.
