So I might be crazy but not insane and here is my problem.. Every time I fill up the car smells like gas is leaking somewhere.. it's strong.. the car does run rich which is part of the problem (which I'm getting this checked out) however it just tends to smell a LOT worse.. I have not seen any gas drips anywhere in front or rear of car... Unless I bump my status up to insane it seems like it smells a lot less when the gas tank is much lower.. am I nuts or could I have a small leak somewhere (gas tank or otherwise) or some fuel pressure issue? Hopefully looking into why it's running so rich though.. I can taste the damn fuel in the exhaust..

 

...I gotta ask, how do you taste your exhaust...? that just sounds like a bad idea.

You may have a rotted vent line or something that is letting fumes out when the tank is full.

 

my 89 formula has the same issue but only when its full. after a bit it dies down and its not just inside the car but outside as well, I had a friend park behind it an hour or so after I had filled it and she asked if it was leaking gas from the smell, also my fuel gauge is about a quarter tank off and my car sputters and runs like ****. not sure whats up but its obnoxious to say the least.

 

lol.. well when it's especially humid out it can make it more potent.. it's just really strong

 

Fair enough, haha.

Have you looked to see if someone put at access hatch in your car under the rear carpet? That could be leaking fumes as well.

 

yup.. exactly.. except I don't have the the fuel gauge problem and the car doesn't sputter or run bad.. just at times it will stall after coming to a stop or really low idle.. like backing up.. I think that has to do with it running way too rich.. it's really driving me crazy..

ideas?

a leak in the gas tank
leaky/shorting fuel injectors
o2 sensor
a bad wire, distributor/cap/rotor
wrong gaps on plugs
air filter (have k&n and it looks clean) going to clean it anyways.. sigh
fuel regulator/pressure
ecm/chip because this had a 305 to 350 swap
egr valve - noticed infrequently at high speeds will trigger check engine light, however turns off as during drive and every time I turn the key to off
a random hose that is cracked or disconnected

will this list ever end?

 

actually no I haven't.. that's a good suggestion.. I will check that out..

 

My car has a strong gas smell when the tank is full. Happened after i swapped my regulator. I'm guessing either I didn't seat something properly or I have a broken vent line or the like.

 

OP, I notice you have a '91. If memory serves there was a recall on the gas tanks because of the lead free solder they used to join the filler neck to the tank, therefore causing a weak solder joint(s), or simply a slight crack. That could be why you smell gas.

I suffer a similar problem with my '92. I can see evidence of a leak at the neck when looking from underneath, but the smell usually goes away after a few miles and I don't notice it again until the next time I fill up.

 

Oh wow.. now this is eye opening!!! I bet that is it.. mine smells for a lot more than a few miles and not sure if it's something that dries out without driving or until I get to a certain level in the gas tank.. from now on, I'm going to only put in half a tank and see if it smells.. positive it wasn't smelling like it is now at 1/3rd..

any idea how hard of a fix this is and if it's worth it?

 

To fix it you'd have to drop the rear suspension and the tank and re-solder the joint (if you are experienced). I wouldn't worry about it unless you already plan on replacing the fuel pump

Take a peek underneath where the neck meets the tank and see if there's residue from a leak. You should easily see it if it is in fact a leak.

 

is that in the very back of the vehicle or more towards the front? I really want to verify this and I'm certain this is part of my gas smell.. the other is probably leaky fuel injector(s) based on the semi rough idle but when I'm on it, it's not missing.. only at high speeds sometimes the check engine light comes on I think due to some EGR valve condition.. then the light will sometimes go off before I even turn the key off.. when I do turn it off it will not come back on until some random point going 50+ mph

 

I'm 99.9% sure I just found the culprit.. the hacks who did the engine swap decided to leave the memcal of the 305 5.0 in it...

REALLY???? Who does a full engine swap and doesn't replace probably the most important part? So now who knows if they jacked with the timing or something when they did the swap.. Thanks to Brian @Tuned Performance helping me step by step and troubleshooting this!! I wonder how much better the car will perform once I get the proper chip in it etc...

 

I replaced tank on mine . was pouring out after fill up. If the top (circle ) seal of the tank not closed tight it would leak when full. My friend drove behind me after a fill up and it was leaving a small trail of gas when full . no problems now. But Dropping the tank sucks.

 

yeah i'm just going to fill it up 2/3 or 3/4 and see if it smells bad.. if not then I will fill it to the highest level each time I fill up..

 

is it just running really rich?

 

That's not going to cause your raw fuel smell. Mine did this and it was a cracked neck. I just replaced my tank with a new dorman for $160 along with a new filter and pump since I was already there.

Heres a test. Fill up to about 3/4 tank. Park on a driveway. Watch the fuel leak down from the heat shield on the driver side. Heres another test, when you remove the gas cap do you have vapor release?

 

If your tank is slightly pressurized with the vapor isn't that just a clothes purge valve?

 

Our systems are designed to run with about 2PSI of pressure in the tank. When you undo the cap and get some release that tells you the system is sealed. For example.

With my filler neck cracked, I smelled raw fuel every fill up and when removing the cap had no pressure release. Since replacing my tank a few days ago, no fuel smells, and now the system is sealed and releases vapor when pulling the cap.

 

Yeah I have zero pressure release. I noticed that when I have re-fueled.. well I'm not looking to replace it unless absolutely necessary. I would assume this really doesn't have any overall impact on the performance of the car, right?

 

It didn't to mine, I think I lost a couple MPG but I'm not sure that is related. At any rate, Its nice to be able to actually fill it up now

 

Yeah that is one thing that would be nice.. if I ever do it I will check the fuel pump and see if that needs replacing because I hear it's a major pita to drop the tank etc..

 

If you are already there, don't even bother checking it. Just replace it. Acdelco pumps only run about $40 from rock auto. Save your self a second drop.

 

how much is the fix for the gas tank and or a known good/new one?

 

Don't bother trying to fix it if its a cracked neck. No one with brains will solder a used tank.

I got my new tank from summit who price matched amazon at $161 shipped. Along with the pump, strainer, and fuel filter total cost will be $240 if you do the work yourself and opt for the higher flow TPI pump like I did.

Tank is dorman. Filter, pump, and strainer were all acdelco

 

Cool, thanks for the heads up!!

 

Hi, i have the same freakn problem. When i'm at idle my car stinks and you can smell the gas fumes. Its making me sick and i really want to look for that problem. I love my camaro and i really enjoy it too. I have no idea where to start, can anyone guide me to where to look first?
Thank you,

 

Check the filler neck. Does it leak out?

 

It doesn't help that my car is running crazy rich as well.. however I'm hoping to possibly alleviate that issue tomorrow by installing the proper memcal.. I still think there could be something else causing it.. but my as tank is definitely hosed.. going to only fill up half a tank and see what happens.. but if the leak is from where you insert the gas pump I'm pretty much screwed everytime..

 

Hello RS-Chevy-SS, i got a new gas tank with filler installed, today i removed the gas cap and i didn't hear the vapor release. Any ideas?
Thank you,

 

RS-Chevy-SS, i also forgot to mention got the fuel sending unit replaced as well, since the hard lines were cut and damaged from a previous owner. My fuel gauge is also off by 1/4 tank when i fill up.

 

Who did the replacement? Could be a multitude of things. First make sure the cap is on right and sealing. If its old, replace it. They are like $6. Then I would suspect the o ring for the sending unit wasn't seated right. If you verify that's on correctly then the only other thing would be a breached neck or tank, or a break in the evap lines

 

Hello RS-Chevy-SS, i ended up replacing the spark plugs and i changed the gas cap too. I don't have that smell anymore, plus it had a misfire. It was running like crap. After replacing the spark plugs and gas cap, i took it for a test drve and it drove better and i opened the window just to make sure, didn't have that smell anymore, plus my gas tank was full too. When i replaced the spark plugs some were really bad and smelled like gas. I'm hoping that's what it was along. Now i just have another problem, i need to replace the speedometer cable, it also has the cruise control. I'm not to worry about the cruise control, just my speedometer. The odometer and the needle don't move. I took it for a tranny service and i thought i had the right cable, so i told the mechanic to check it out and if it needed to be changed to go ahead and do it since i had the cable. Well turned out he noticed i had two, and one was really bad at the tranny the pins were bad. So he said the one i had wasn't the correct cable. By any chance does anyone know which one i need? Or a part number?
Thank you,

89 camaro RS with 305 TBI

 

So a partial update on mine... car was not running rich (plugs were new and had good wear/color), however timing was set to 9 degrees btdc.. now it's set properly to 6.. also found out the vapor canister could be bad, charcoal not doing it's job possibly or the solenoid not letting vapors pass into the engine or something.. We pulled the canister and it didn't seem like there was raw gas in it.. what the heck else could it be if it's not a bad canister?