70 Trans Am strong fuel odor after driving.
 

I have a new to me 70 Trans Am, RA3 4-speed. Trying to sort out some issues. First up is a VERY strong fuel odor after driving. Not as noticeable under the hood, seems to be from the rear of the car, gas tank area. I have checked the rubber lines under the passenger seat, they seem fine, no leaks.

Any suggestions before I drop the tank to check all the lines?

This have EEC? Seen those plastic "boxes" leak with modern fuel, and its warm enough there to vaporize it instantly.

This was a California car, so yes it has the EEC. The canister under the hood has been disconnected, I guess I will need to figure this out as well.

All 5 hose connections can be seen and serviced without dropping the tank. Two are from the sending unit which is hard piped from the top to the two longer hoses on the upper front passenger side. Three other connections are short pieces connecting to chassis mounted hard lines. Best to have a lift for easier access.

The EEC is ABOVE the factory crossflow Muffler, and is the Piece I am talking about. It is 1970 Cailf car only. Also used a canister up front, but smell is out back.
I have a set up off a 1970 Formula if you need pics.
These were FACTORY installed in California built AND Norwood built Firebirds Sold in California.
https://forums.maxperformanceinc.com...1&d=1678135047
https://forums.maxperformanceinc.com...3&d=1678135058

Can this be bypassed? Or is it something that is needed?

That's probably the start of the issue. Sounds like it's been monkeyed with. Not surprising to see that, as most people really don't understand how that system functions to vent the tank and quickly start removing parts and disconnecting hoses.

With it all hooked up and working properly, you won't have any gas smell.

My 70 Formula built and sold in California has all the stuff Formulabruce mentioned, hooked up and working.

Me personally, I'd go through the whole system checking lines and get everything hooked back up as it should be and go from there.

Does anyone know if a replacement canister that mounts above the tank, is it available today? or something that would function in its place?

If you're referring to the piece that Formulabruce pictured, I think they call that the separator assembly.

I don't recall seeing those sold new anywhere but I would think they would be. You can buy the charcoal cannisters new so I would think the separator would be available somewhere.

The EEC set up ( separator) in my pics? No, not available aftermarket because of the '75 and older rule in calif? I think that's the cut off for must have all the emission.
I would sell what I have in the pic if needed and it has never seen any alcohol fuel. Obviously new high heat fuel lines are required. You should be able to get it going without too much trouble. Does your car have the EEC unit and the front canister still in the car?

Yes it still has the EEC and the front canister, so I hope I can get this reconnected and working without too many issues.

Anyone have a diagram on how this all hooks up?

Looking for a diagram on how the EEC system is laid out.

I have that but cant get to it for a few days. May be in the 70 Firebird suplement manual.

Can someone tell me the correct size fuel line hose and the hose size for the vapor lines?

This “vapor separator” is intended to keep liquid gasoline from making its way to the canister. Liquid fuel can deactivate the charcoal. Unfortunately the 70 only California-only separator was replaced by the standpipe set up behind the rear seat on all 71 and later 2nd gens. I suspect once you connect everything your fuel smell issue will be solved.

Do you have a vented fuel cap ?

Send me an email and I can send you some pics from assembly manual.


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:)

No it is non-vented

Email sent

My emails were getting bounced back.

Try this link:

1970 Vapor Separator


:)