Fuel smell

[mtiger_dds]

I've been getting a strong fuel smell in my 73 that seems to be localized to the trunk while the car is running. Of course, it finds its way into the cabin.

There are no visible leaks at the tank or any of the lines/hoses. Reading on the e9 forums, the prime suspect seems to be the vapor collection tank over the right passenger wheel well. At least with the e9's, the solutions seem to be replacing various gaskets, charcoal filters under the battery, or venting the vapor tank to the outside of the car. I'm not familiar enough with the e3 and e9 at this point to recognize similarities amongst the two models.

Any tips, tricks, recommendations?

 

[bavbob]

The plastic lines that go to/from to the vapor tank are brittle and crack. Cracks may not be visible. Also check around fuel sender unit at the tank and the line going from the sender unit to the metal fuel line that exits the trunk.

 

[Ohmess]

My car is a 72 e9 with carbs, but I'll take a shot at this.

The plastic expansion tank in the trunk and the charcoal filter under the battery are designed to trap gasoline vapors and hold them temporarily. There should be a hose from the charcoal canister to the air cleaner which draws the trapped vapors into the air cleaner and then into the carbs when engine vacuum is high.

If your system has been disassembled in the past (as most of ours have), it may not have been put together properly. In particular, if the hose to the air cleaner is missing or disconnected, the trapped vapors will not be drawn through the system, and may leak out elsewhere. That would be the first thing to check.

And, of course, if you are running triple webers like I am, there is no place to connect this hose. (I run a rubber hose downward from the carbon filter, venting the vapors as I drive. I don't pull anything extraneous through my carbs so as to avoid gunking them up faster).

Also, there are rubber hoses from the fuel filler neck to the hard plastic line and at both connections of the hard lines to and from the expansion tank. If those hoses are damaged or not connected properly, you will have gasoline vapors in the trunk. Also, as noted, the hoses that run to and from the expansion tank are made from a hard plastic that can become brittle, but I would think the hose connections a more likely source of trouble.

Another potential source of trouble is the gasket at the top of the fuel level sender. Mine was rotted and hard and when I had more than 3/4 of a tank would allow fuel to seep onto the top of the tank.

 

[Keshav]

"Another potential source of trouble is the gasket at the top of the fuel level sender. Mine was rotted and hard and when I had more than 3/4 of a tank would allow fuel to seep onto the top of the tank"

Potential culprit is the gasket(s) of the fuel sender unit>tank getting brittle and gas evaporating smell. Had exactly that symptom recently.

 

[bluecoupe30!]

I've been getting a strong fuel smell in my 73 that seems to be localized to the trunk while the car is running. Of course, it finds its way into the cabin.

There are no visible leaks at the tank or any of the lines/hoses. Reading on the e9 forums, the prime suspect seems to be the vapor collection tank over the right passenger wheel well. At least with the e9's, the solutions seem to be replacing various gaskets, charcoal filters under the battery, or venting the vapor tank to the outside of the car. I'm not familiar enough with the e3 and e9 at this point to recognize similarities amongst the two models.

Any tips, tricks, recommendations?

Wondering if this is a recent experience, has it been fine in previous years of use, or earlier this year even. Have you been driving it more this summer? Perhaps use has loosened the fittings. I tend to favour the fuel level sender as well. If you haven't looked at what's connected to your gas tank recently, it is a great starting point.

 

[Stevehose]

Disconnect the tube that goes from the filler neck to the trunk cannister and cap the cannister. Run another line from the neck out the trunk floor between the gas tank and rear of car. Should be a hole their already. Check the sender unit gasket. Problem solved.

 

[mtiger_dds]

It was faint in the past, but has been stronger over the past two weeks. I just got the car in April.

I pulled the vapor tank from the trunk. It's sound, the hose leading into it is suspect.

The charcoal canister in the engine bay appears original and the hoses going to it are shot. I ordered the canister and I'm off to buy some new hoses.

Thanks!

 

[HB Chris]

And be sure you have a good trunk seal too. Thank you for going a little bit extra and keeping your evap system, even though the emissions are probably very small I would rather burn it in the engine than vent it to the outside.

 

[mtiger_dds]

I installed a new trunk seal a few months ago, so it's good. I was getting rainwater in the trunk, and I still do from from time to time. I think it's coming from the tailights, primarily the driver's side.

The car smells much better even with just the trunk re-plumbed.

 

[Joe Barthlow]

I've experienced this recently too

 

[Ohmess]

It was faint in the past, but has been stronger over the past two weeks. I just got the car in April.

I pulled the vapor tank from the trunk. It's sound, the hose leading into it is suspect.

The charcoal canister in the engine bay appears original and the hoses going to it are shot. I ordered the canister and I'm off to buy some new hoses.

Thanks!

The charcoal canister is only useful if connected to the vapor tank. The system is designed to capture vapors in both the vapor tank and in the charcoal canister. If you are seeking to keep the system intact, you need the vapor canister and the connecting hoses. Consider too that you can use fuel hoses to replace sections of the hard plastic hose.

 

[mtiger_dds]

Charcoal canister went in Tuesday, and all hoses except for the hard plastic one that goes through the car were replaced. Huge difference!