Fuel smell when car is parked

[streetk14]

I've had a little fuel system gremlin for a while on my '68 camaro. I have yet to spend any time diagnosing it, but I was looking for some opinions on it's possible cause. There are 2 problems that I am sure are related. 1) there is a fuel smell coming from the car when it is parked in the garage. There are no obvious leaks, and I don't smell anything while driving. 2) The car is very hard to start if it hasn't been driven in more than a week or 2. I need to crank it for 30 seconds or so before it will start. If the car has been driven within the last few days all that is needed is a pump of the accelerator pedal and the engine will fire with a tap of the key.
There are a couple of things that I think could be happening. The fuel could be draining back to the cell when the car sits. This would explain the long crank condition. If this is the case then maybe the fuel odor is coming from the vent tube in the cell? Although, I'm not sure WHY this would happen.
The other thought I had was that fuel could be leaking into the carb while the car sits, flooding the engine. Maybe a needle & seat problem or nitrous fuel solenoid leaking?
My fuel system consists of a trunk mounted RCI cell, -6 Aeroquip push-lock style hose, Edelbrock street fuel pump and an Edelbrock 750 carb. I also have an auxillary fuel system that uses a rear mounted Holley blue pump with an under-hood pressure regulator that feeds the Edelbrock nitrous system. I haven't used the nitrous or fuel pump in a long time. I am planning to install a completly new fuel system soon, but I'd like to know what is causing this. The fuel vapors in the garage can't be a good thing. Any ideas?
-Andy

[LowBuckX]

My guess fuel smell = properly working vent tube.
Fix= hoopk up the charcoal canister again or live with it..

[streetk14]

I know that you will get vapors from the vent tube to a certain degree but I'm thinking something else is going on. It's the long-crank thing after the car sit a little while that gets me. I suppose if the fuel was draining back to the tank after the car was parked, the vent tube would release a noticable amount of vapors. I don't think this is supposed to happen though. I guess I should probably check out the carb after the car sits for a week. See if there is any fuel in the line.
-Andy

[Norwoodx55]

Even if the line is draining back, there should be more than enough fuel in the bowl. Don't have any more suggestions for you though.

[whytry]

I am in the same boat here, have been searching for awhile on this topic, and I have the same smell in my garage too. I am thinking of adding the cannister, but not sure how to do it...

[mdprovee]

Also heard if you are running braided steel hose for the entire length of your car, that the hose will "leak" small amounts of fuel thru the rubber line and cause fumes. Not enough to drip on the ground though.

[whytry]

I have hard line for most of the car. The only places that are steel braided are from the Sumped tank to the pump, 6" after pump then to hardline and then from the hardline to regulator, and flex from the regulator to the carb. I am running the Earl's line too, I read the Russell can sweat the most....


Can I run something like a PCV valve on the end of the vent line attached to a crankcase breather up in the rt rear fenderwell?

I have the stock tank sumped, and added a new return line, and was using the stock feed line for nothing, I think I have it cut off and bent upwards so no fuel spills out. I am also running the vented gas cap... Help....

[kenhaw]

Well this is an old thread and I dont know if anybody found a solution for this.
I also have a vented cap but still when I open it there is clearly pressure in the tank. It doesn´t seem to cause any problems with my carb but have read that it might flood the carb because of the pressure.
Is my tank cap faulty or is some pressure in the tank normal?

[Vegas69]

There should be no pressure in these old cars. Rule of thumb is you need a vent for you tank no smaller than the size of your feed line to the engine.

[kenhaw]

There should be no pressure in these old cars. Rule of thumb is you need a vent for you tank no smaller than the size of your feed line to the engine.

Have just had my tank off to change the intank sending unit. I have no vent hole in my tank. It is a 69 Camaro.
I do however have a 1/2" return line fitting which I am not using, can I use that and will I have to install some kind of special gizmo on that if so?

[Damn True]

Also heard if you are running braided steel hose for the entire length of your car, that the hose will "leak" small amounts of fuel thru the rubber line and cause fumes. Not enough to drip on the ground though.


My gut feeling is the same.

[kenhaw]

honestly, doesn´t big american muscle by definition have to smell of gas. Wouldn´t be the same experience without it.:)

[Vegas69]

I am running the Pro flo 350 and a 1/2 bent. I am running 2/3rds hard line however. I don't get the fuel smell unless it gets really hot in the garage.

[kenhaw]

I am running the Pro flo 350 and a 1/2 bent. I am running 2/3rds hard line however. I don't get the fuel smell unless it gets really hot in the garage.


Hi Todd.

I am running the same flexible hose. Most of my line is flexible except for a long 1/2" aluminium piece running along under the door.
Could you give me any hints regarding the lack of a vent tube in my tank? Can I use the spare 1/2" return line fitting and just uncap it or do I need to put anything on the fitting?

[Vegas69]

I have mine run up to a K+N filter above the tank. Last time I talked to Aeromotive they recommended a couple loops of hose to keep it from overflowing when filling the tank.

[parsonsj]

Here's a solution to the vent issue, along with the gas smell.

https://www.pro-touring.com/forum/showthread.php?t=51287&highlight=fuel+vent

jp

[Ranaexcavating]

It sounds like your fuel is boiling after the engine is shut down. I had the same issue and installed the Edelbrock spacer to stop the heat from the manifold getting to the carb. Worked like a charm!