Fuel return lines and vents

[E60coyote]

Hi there.  I recently acquired a ‘76 ‘02 and need some help sorting out the fuel lines.  The P.O. installed an electric fuel pump in the trunk and removed the return valve and the charcoal canister for the vent.  I can only find one line going to the engine compartment and that is the supply line which has been ‘upgraded’ to an aluminum tube. The return from the tank is routed to the plastic vent canister in the trunk. See pictures. 

 

My questions: 

 

- Is this vent setup working at all? I do get a slight gas smell in the trunk. 

- should I add back the return valve and reconnect to the tank?  Where does this line enter the engine compartment? The line is in the trunk but I can’t find the other end.

- should I add back the charcoal filter and route to the air Filter?  How/where do I connect it to the aftermarket air filter I have?

 

thanks for your advice!

Edited July 7, 2018 by E60coyote
Autocorrect...

[Chris_B]

Here are a few quick and dirty responses to your questions:

 

- Is this vent setup working at all? I do get a slight gas smell in the trunk. 

The gas smell in the trunk is hardly unusual. It may or may not be related to your vent setup. It may be working, in that those lines from the fuel filler and tank terminate somewhere. They could be plugged, but who knows? You need to follow them and determine that.

 

- should I add back the return valve and reconnect to the tank?  

Not really necessary,.

 

-Where does this line enter the engine compartment? The line is i. The trunk but I can’t find the other end.

Not entirely sure what you are saying, but the original vent line runs to a tank in the trunk and then up the right side of the car and terminates in the right front where the vapor tank is (was) located. You did not provide any pics of the part of your engine bay, so kind of hard to tell what is happening up there.

 

- should I add back the charcoal filter

Yes, If you want to be environmentally responsible.

 

and route to the air Filter?  

Yes

 

How/where do I connect it to the aftermarket air filter I have?

There is a lot of sucking going on there. You can get devices to attach your vent hose from the charcoal filter to the air filter.

 

No doubt, the above is wrong in some details.

[Simeon]

The canister needs to be ‘drawn off’ somewhere. If it is open to atmosphere in the trunk then that’s where your smell is coming from. The tank is venting into the canister from two places. The return pipe is possibly too low any you may get some fuel siphon up to the tank. The vent from the top of the filler neck is the correct one. 

 

You can run it Euro style if you like by taking a pipe from the top of the filler neck down to the hole in the centre / rear under the floorboards which should have a rubber bung in it. Replace this with a grommet and run the pipe through there to fresh air. 

[Son of Marty]

Good advice above on a 76 the charcoal canister would be mounted to the brake booster bracket, Probably the simplest thing would be to plug off the return at the tank and use the euro vent out the trunk floor.

[E60coyote]

Thanks so far! So basically I need to get the vent redone either Euro style or Orginal but not worry about the return. Just cap it at the tank. 

 

There is no charcoal canister either front right or under the break booster...

 

what about going back to the mechanical fuel pump? Adviseable?

[aaron7302]

Yep, looks to.me, that if you have a hose going from tank to plastic tank, then a hose from plastic tank to filler neck, your vent is not venting and you could encounter vapor lock. As others have said, plug the line exiting tank, run filler neck line to outside trunk atmosphere. Some gas smell in garage but not in trunk. Be sure the return line itself is plugged, from under the battery where it starts and also where it ends the trunk.

 

As for fuel pump, a debatable item but if you stick with electric, check to see if an inertia cut off switch is installed in the event of an accident, and consider ordering/carry a replacement pump as they fail without notice. And it depends how noisy it is to you and how "original" looking you want the car.

Edited July 7, 2018 by aaron7302

[E60coyote]

Thanks!  Found the return line under the battery.  Still can’t locate the vent line. Must have been removed. 

 

Good point about the inertia cutoff. I will try to see if there is one but I don’t it based on all of the other hacks I’ve found so far!