Fuel line that goes to nothing

[Dawskip]

The other day my 2002 developed a fuel leak form the hardline that runs along the driver side. I managed to get it home, only to discover that the line goes to nothing?

 

I ran it back to the tank and it’s not the line from the sender but the tank itself. To my knowledge this was a fuel feed line, that ran up into a fuel filter by the radiator. Right now I have Weber 40s and the fuel comes from up by the firewall, is this supposed to be the return line?

 

how should I properly route this?

['76mintgrün'02]

The metal line on the driver's side is the return line for cars with carbs and it is the supply line for the Tii.  If you are not going to use it, it is best to cap the nipple at the tank and blow the fuel out of the line and then cap that too, to keep dirt and bugs out of it.

 

If you use the search feature and type "Jeep filter", you will see a ton of discussion about using that filter to feed the return line.  (That's what I do).

Tom

[John76]

Be sure to keep the vent tube that connects to the rubber boot on the tank (inside trunk). The gas cap is sealed, and this vent is needed to prevent vacuum from building as the tank empties. 

Are you using an electric pump with your Webers?  The blue plastic fuel supply line that runs through the passenger compartment is designed to suck fuel from the tank by the mechanical fuel pump on the engine...no big deal. 

If you have an electric pump, it should be mounted near the fuel tank and use the metal gas line that runs under the car on the driver's side. This is pressurized fuel all the way to the engine bay....don't use the plastic tube for this!

 

Here's a sketch of the original fuel system for a carb with mechanical fuel pump.

 

 

[Dawskip]

1 minute ago, John76 said:

Be sure to keep the vent tube that connects to the rubber boot on the tank (inside trunk). The gas cap is sealed, and this vent is needed to prevent vacuum from building as the tank empties. 

Are you using an electric pump with your Webers?  The blue plastic fuel supply line that runs through the passenger compartment is designed to suck fuel from the tank by the mechanical fuel pump on the engine...no big deal. 

If you have an electric pump, it should be mounted near the fuel tank and use the metal gas line that runs under the car on the driver's side. This is pressurized fuel all the way to the engine bay....don't use the plastic tube for this!

 

Here's a sketch of the original fuel system for a carb with mechanical fuel pump.

 

 

Gotcha.

 

The current state of the car is this:

 

I capped off the line from the gas tank right at the tank, took the metal line out as it was rusted very badly. 
 

the plastic line that runs from the fuel sender appears to be the one that runs to my electric pump (located right up front by the brake booster). 
 

I don’t deel 100% safe with this setup so I’m not driving by it currently, is there a better way to go about it?

[John76]

The electric pump should not be in the trunk or the engine compartment (for safety reasons).

Electric pumps like to "push" fuel...they are not very good at "sucking", therefore should be mounted near and below the tank.

I would replace the steel gas line and use it for the supply to the carbs. No need for a return line, unless you are plagued with vapor lock on hot restarts. Return line keeps gas flowing (and cool). You could use the plastic line for the return if needed.

[AustrianVespaGuy]

Having a return fuel loop is a good idea for several reasons.  As mentioned, it helps prevent vapor lock when hot by keeping cool fuel circulating, and it also it helps with longevity for both the pump and carbs.  With no return, the pump ends up running most of the time against the closed float needle(s). This constant-pressure-but-no-flow stresses both the needle seat, causing it to start leaking sooner, and doesn't do the pump any favors either.

[Dawskip]

2 hours ago, AustrianVespaGuy said:

Having a return fuel loop is a good idea for several reasons.  As mentioned, it helps prevent vapor lock when hot by keeping cool fuel circulating, and it also it helps with longevity for both the pump and carbs.  With no return, the pump ends up running most of the time against the closed float needle(s). This constant-pressure-but-no-flow stresses both the needle seat, causing it to start leaking sooner, and doesn't do the pump any favors either.

What would be the best way to add one into the loop?

['76mintgrün'02]

4 minutes ago, Dawskip said:

What would be the best way to add one into the loop?

 

10 hours ago, John76 said:

Electric pumps like to "push" fuel...they are not very good at "sucking", therefore should be mounted near and below the tank.

 

I would replace the steel gas line and use it for the supply to the carbs. No need for a return line, unless you are plagued with vapor lock on hot restarts. Return line keeps gas flowing (and cool). You could use the plastic line for the return if needed.

 

Was your steel line deeply pitted, or just rusty looking?  Mine actually rusted through down where it passes the pedal box, but otherwise it's fine.  I just spliced a piece of rubber line into that section when I put the steel line back into service.

Tom

[Dawskip]

Just now, '76mintgrün'02 said:

 

 

Was your steel line deeply pitted, or just rusty looking?  Mine actually rusted through down where it passes the pedal box, but otherwise it's fine.  I just spliced a piece of rubber line into that section when I put the steel line back into service.

Tom

It was starting to have several leaks

[AustrianVespaGuy]

11 minutes ago, Dawskip said:

What would be the best way to add one into the loop?

On my EFI car I use the steel exterior one for the supply and plastic interior one for the return. Low pressure carb you could use either line for either direction, and then just need the branch to give you the extra fitting for the return line.

[Dawskip]

4 minutes ago, AustrianVespaGuy said:

On my EFI car I use the steel exterior one for the supply and plastic interior one for the return. Low pressure carb you could use either line for either direction, and then just need the branch to give you the extra fitting for the return line.

Where is the best spot for me to branch out and ate that return line though

[AustrianVespaGuy]

Probably at the firewall; either use the stock 3-way divider or get a pressure regulator with return, and then if you want use one of this nice doodads from IE to feed the carbs:

https://www.iemotorsport.com/product/fuel-rail-for-dual-sidedraft-carbs-m10/

[tech71]

16 hours ago, Dawskip said:

the plastic line that runs from the fuel sender appears to be the one that runs to my electric pump (located right up front by the brake booster). 
 

I don’t deel 100% safe with this setup so I’m not driving by it currently, is there a better way to go about it?

Thats the cars original fuel delivery line, pretty durable actually, as long as it is left alone.

Most 02s are still driving around with it in place and happily delivering fuel. No reason to get nervous.

 

4 hours ago, Dawskip said:

What would be the best way to add one into the loop?

Buy a long length of Cunifer metal line(easier to bend) in appropriate diameter and hand form using the old line as a template (hopefully you still have it), fit where original line ran, slide pieces of heavy heat shrink tube (dont shrink it) to positions where line is retained by the tabs.

Later, if you wish to go FI you could use it as a pressure line but at this point, why bother?

 Whats going on in your engine bay where this rusty return line plumbed in?

Where exactly is your fuel pump mounted? By the brake booster??

A pic is always helpful and easily worth a thousand words.

 

Edited August 14, 2021 by tech71

[Son of Marty]

That fuel rail by Ireland is very pretty but it will crack over time, there's a reason why all the multi carb oem set ups use rubber hoses between carbs and it metal fatigue something stainless steel is not well equipped to handle. For those that are going to say I have one and it works great give it some time. With duel webers and a electric you don't need a return line but you do need a good pressure regulator.   

[John76]

7 hours ago, AustrianVespaGuy said:

This constant-pressure-but-no-flow stresses both the needle seat,

Another benefit to a return line on an electric pump is much quieter operation. The pump is no longer pumping full pressure against a dead end (closed float needle(s).