72 fuel lines and tank

[stoney2677]

I've searched here, nastyz28, and Google but can't find. I've identified the feed line and vent line from the tank. The vent line comes back disappears Under the car heading back towards the front and then goes to the tank. That's the first question, where does it go? That's on the driver side. Feed comes from the center of the tank. There are 2 more lines coming from the passenger side of the tank. I assume one goes to the fuel gauge? What would the other be? I see no charcoal filter anywhere. I'm going to install the atomic efi and was wondering if any of those lines could be used for a return.

[bsharp2]

Did you see this?

http://www.nastyz28.com/forum/showthread.php?t=252193

My 71 has this fuel vapor separator/vent setup behind the back seat.

[bsharp2]

I've got a 72 assembly manual around if you don't have one, kept it when I sold my 72 Z-28.

[BonzoHansen]

Fuel gauge is a wire to the sender in the tank. Evap is a single line that runs up the drivers side. I think by 72 they had moved onto the cannister up front and not the odd setup behind the rear seat. But i'm not sure of that.

The fuel feed line runs up the pass side. There is a rubber hose at the back of the subframe to allow for body mount movement. Some cars had a second smaller line that ran parallel to the fuel feed line. It as actually a return line. Both ran to the fuel pump. I think either all AC cars or all HD cooling cars got the return line. My Z, an AC car, has a return line.

[bsharp2]

Got curious and pulled the AIM... manual shows both the Charcoal Canister and the Vapor Separator for 72. Link above shows page from a 73 book.

[stoney2677]

Originally Posted by bsharp2

Did you see this?

http://www.nastyz28.com/forum/showthread.php?t=252193

My 71 has this fuel vapor separator/vent setup behind the back seat.

Thanks. Can you see it if you pull the back seat forward? The one on my driver side goes all the way to the front and hangs out behind the bumper. That normal?

[stoney2677]

Originally Posted by BonzoHansen

Fuel gauge is a wire to the sender in the tank. Evap is a single line that runs up the drivers side. I think by 72 they had moved onto the cannister up front and not the odd setup behind the rear seat. But i'm not sure of that.

The fuel feed line runs up the pass side. There is a rubber hose at the back of the subframe to allow for body mount movement. Some cars had a second smaller line that ran parallel to the fuel feed line. It as actually a return line. Both ran to the fuel pump. I think either all AC cars or all HD cooling cars got the return line. My Z, an AC car, has a return line.

Mine looks, from what I can see, very similar to the pic. Driver side goes up behind the seat, another comes out and goes up to front of car and vents outside the car. No canister. 2 off passenger side up behind seat.

[bsharp2]

Originally Posted by stoney2677

Thanks. Can you see it if you pull the back seat forward? The one on my driver side goes all the way to the front and hangs out behind the bumper. That normal?

You can see the unit if you pull the upper back seat but the connections face rearward over the tank. If you pull the seat you can at least ascertain if you have this. From there you can use the AIM diagrams to see routing. I can scan pages if you need them.

[stoney2677]

Originally Posted by bsharp2

Got curious and pulled the AIM... manual shows both the Charcoal Canister and the Vapor Separator for 72. Link above shows page from a 73 book.

So I guess the question is can I lose this set up, or some of it, in place of a vented cap? This would make it easy to add a return line w/o dropping the tank. Still can't figure if a 70 vented will fit a 72.

[stoney2677]

Originally Posted by bsharp2

You can see the unit if you pull the upper back seat but the connections face rearward over the tank. If you pull the seat you can at least ascertain if you have this. From there you can use the AIM diagrams to see routing. I can scan pages if you need them.

Thanks but the link you posted shows what I have already.

[bsharp2]

Originally Posted by stoney2677

So I guess the question is can I lose this set up, or some of it, in place of a vented cap? This would make it easy to add a return line w/o dropping the tank. Still can't figure if a 70 vented will fit a 72.

I've never done this but the guy in the thread I linked seems to say this is possible...

"The three-line tanks have a fuel supply, fuel return line, and the line to the charcoal canister. The two line tanks don't have the return line.

You don't generally need to run a return line if you're running a mechanical pump.

You do need one (highly recommended?) if you have an electrical pump.

You must vent your tank in some way or you will have fuel delivery problems.

To vent your tank you can either leave the line hooked to the charcoal canister or you can install a small breather filter on the end of the line somewhere and remove the charcoal canister. You may smell more fumes if you do this.

You can also use a vented gas cap to allow air into your tank."

[stoney2677]

Thanks for all the replies. I'm gonna try a vented gas cap and also leave the front vent. This way one can stop the vacuum effect and the other will release any pressure built from heat. If I have problems I'll bite the bullet and buy a new tank.

[bsharp2]

Originally Posted by stoney2677

Thanks for all the replies. I'm gonna try a vented gas cap and also leave the front vent. This way one can stop the vacuum effect and the other will release any pressure built from heat. If I have problems I'll bite the bullet and buy a new tank.

Best of luck with it! I'm sure I'll be dealing with it on my 71 at some point but it's all apart now so I'm probably just running all new lines.