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> Fuel tank line access question
stevegm
post Feb 23 2020, 06:04 PM
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EDIT:

I think I’ve found the problem. See the last post.

———


I’m getting my engine broken in with a single carb. The fuel pump is located in the engine compartment. When I hook the carb up to the fuel line in the car, it doesn’t get fuel. The pump never quiets down, and no fuel.

When I put a fuel line from the fuel pump directly to a gas can next to the car, it takes fuel and runs fine. The pump quiets down once it gets fuel. Everything works fine.

When I blow air back through the fuel line from the engine compartment, with an air hose, you can hear it coming out in the gas tank. So I don’t think the lines are clogged.

Any ideas why I’m not getting fuel out of the main line with the pump? The line is a hard line. It looks like someone has replaced the plastic lines. The car had carbs when I bought it a few years ago.
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MJHanna
post Feb 23 2020, 06:16 PM
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Most fuel pumps are pusher pumps they like being close the fuel tank and push the fuel to the carbs. They have a tuff time pulling the fuel the entire length of the car. Also leaving it in the engine compartment it can vaper lock from the heat of the engine after it sits for a while. When you put it in the gas can it is a short distance and is pushing the fuel to the carb. Porsche moved the fuel pump to the front of the car to stop the issue of vaper lock.
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iankarr
post Feb 23 2020, 06:22 PM
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Assuming the tank isn't close to empty, the fuel pump should be supplied from gravity alone. Is the fuel sock clean?
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stevegm
post Feb 23 2020, 06:29 PM
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QUOTE(cuddy_k @ Feb 23 2020, 07:22 PM) *

Assuming the tank isn't close to empty, the fuel pump should be supplied from gravity alone. Is the fuel sock clean?



Where/what is the “fuel sock?”
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dlee6204
post Feb 23 2020, 06:59 PM
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QUOTE(stevegm @ Feb 23 2020, 07:29 PM) *

QUOTE(cuddy_k @ Feb 23 2020, 07:22 PM) *

Assuming the tank isn't close to empty, the fuel pump should be supplied from gravity alone. Is the fuel sock clean?



Where/what is the “fuel sock?”


It is a small screen/filter on the supply line leaving the gas tank.
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stevegm
post Feb 23 2020, 07:00 PM
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QUOTE(MJHanna @ Feb 23 2020, 07:16 PM) *

Most fuel pumps are pusher pumps they like being close the fuel tank and push the fuel to the carbs. They have a tuff time pulling the fuel the entire length of the car. Also leaving it in the engine compartment it can vaper lock from the heat of the engine after it sits for a while. When you put it in the gas can it is a short distance and is pushing the fuel to the carb. Porsche moved the fuel pump to the front of the car to stop the issue of vaper lock.



Thanks. I have dealt with vapor lock with other cars in the past. I’m just surprised this one won’t run at all with the pump. I was considering the possibility that I have a weak pump? If I decide to relocate the pump, can it be put under the car, above the front suspension bolt-on pan, and tie into the fuel line under the tank their? I’d rather not cut/drill to put it in the front trunk, and I don’t have a lot of time this week to do an in-depth installations.
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MJHanna
post Feb 23 2020, 08:03 PM
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QUOTE(stevegm @ Feb 23 2020, 07:00 PM) *

QUOTE(MJHanna @ Feb 23 2020, 07:16 PM) *

Most fuel pumps are pusher pumps they like being close the fuel tank and push the fuel to the carbs. They have a tuff time pulling the fuel the entire length of the car. Also leaving it in the engine compartment it can vaper lock from the heat of the engine after it sits for a while. When you put it in the gas can it is a short distance and is pushing the fuel to the carb. Porsche moved the fuel pump to the front of the car to stop the issue of vaper lock.



Thanks. I have dealt with vapor lock with other cars in the past. I’m just surprised this one won’t run at all with the pump. I was considering the possibility that I have a weak pump? If I decide to relocate the pump, can it be put under the car, above the front suspension bolt-on pan, and tie into the fuel line under the tank their? I’d rather not cut/drill to put it in the front trunk, and I don’t have a lot of time this week to do an in-depth installations.


under the car, above the front suspension bolt-on pan, and tie into the fuel line under the tank their?

Yes that is where 99% of them are located, you take off the pan and put it in there the pan helps protect it from dirt and getting road debris.
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stevegm
post Feb 27 2020, 08:32 PM
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I think I’ve found the culprit. It looks like the previous owner used a very long fuel line from the tank to the main center console hard line, and it might have gotten kinked when the tank was put down in its spot. They probably used a long line because it’s easier to get it hooked up.

Here is my question - if I use a very short line, can I access it to hook it up, through the round hole beneath the tank (photo below), from beneath the car?


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mepstein
post Feb 27 2020, 08:37 PM
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Yes. It's a little tight but that's how it was done at the factory.
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poorsche914
post Feb 27 2020, 08:38 PM
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QUOTE(stevegm @ Feb 27 2020, 09:32 PM) *
... Here is my question - if I use a very short line, can I access it to hook it up, through the round hole beneath the tank (photo below), from beneath the car?

I don't think so, at least not easily.
Shorten the current line a bit if needed and lower the tank so it doesn't get kinked. Maybe access the fuel line through the hole to help position it. (IMG:style_emoticons/default/confused24.gif)

EDIT: well, maybe you can??? I never could (IMG:style_emoticons/default/dry.gif)
steve
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Jamie
post Feb 27 2020, 08:52 PM
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[quote name='poorsche914' date='Feb 27 2020, 06:38 PM' post='2789812']before s my question - if I use a very short line, can I access it to hook it up, through the round hole beneath the tank (photo below), from beneath the car? [/quote]
I don't think so, at least not easily.
Shorten the current line a bit if needed and lower the tank so it doesn't get kinked. Maybe access the fuel line through the hole to help position it. (IMG:style_emoticons/default/confused24.gif)

EDIT: well, maybe you can??? I never could (IMG:style_emoticons/default/dry.gif)
steve
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[/quote]
It really helps to have a longer fuel line so that you can form a complete loop between tank and supply line into tunnel. There is then less chance of forming a kink that will cut off supply from tank. (IMG:style_emoticons/default/barf.gif) I eliminated the notoriously troublesome sock filter in the tank, and have a filter installed before pump up front and another filter in the engine compartment.
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mepstein
post Feb 27 2020, 08:58 PM
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[quote name='Jamie' date='Feb 27 2020, 09:52 PM' post='2789817']
[quote name='poorsche914' date='Feb 27 2020, 06:38 PM' post='2789812']before s my question - if I use a very short line, can I access it to hook it up, through the round hole beneath the tank (photo below), from beneath the car? [/quote]
I don't think so, at least not easily.
Shorten the current line a bit if needed and lower the tank so it doesn't get kinked. Maybe access the fuel line through the hole to help position it. (IMG:style_emoticons/default/confused24.gif)

EDIT: well, maybe you can??? I never could (IMG:style_emoticons/default/dry.gif)
steve
(IMG:style_emoticons/default/driving.gif)
[/quote]
It really helps to have a longer fuel line so that you can form a complete loop between tank and supply line into tunnel. There is then less chance of forming a kink that will cut off supply from tank. (IMG:style_emoticons/default/barf.gif) I eliminated the notoriously troublesome sock filter in the tank, and have a filter installed before pump up front and another filter in the engine compartment.
[/quote]

I disagree. All my cars were refitted with Tangerine racing SS fuel lines and new high pressure rubber line. The small length of rubber fuel line has never kinked. A long screwdriver keeps your hand from blocking your view. Just use a small led light to inspect your work and remember the proper type of fuel clamps. I also put a touch of MMO in the line so it slips onto the tank easily.
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stevegm
post Feb 27 2020, 09:06 PM
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[quote name='mepstein' date='Feb 27 2020, 09:58 PM' post='2789819']
[quote name='Jamie' date='Feb 27 2020, 09:52 PM' post='2789817']
[quote name='poorsche914' date='Feb 27 2020, 06:38 PM' post='2789812']before s my question - if I use a very short line, can I access it to hook it up, through the round hole beneath the tank (photo below), from beneath the car? [/quote]
I don't think so, at least not easily.
Shorten the current line a bit if needed and lower the tank so it doesn't get kinked. Maybe access the fuel line through the hole to help position it. (IMG:style_emoticons/default/confused24.gif)

EDIT: well, maybe you can??? I never could (IMG:style_emoticons/default/dry.gif)
steve
(IMG:style_emoticons/default/driving.gif)
[/quote]
It really helps to have a longer fuel line so that you can form a complete loop between tank and supply line into tunnel. There is then less chance of forming a kink that will cut off supply from tank. (IMG:style_emoticons/default/barf.gif) I eliminated the notoriously troublesome sock filter in the tank, and have a filter installed before pump up front and another filter in the engine compartment.
[/quote]

I disagree. All my cars were refitted with Tangerine racing SS fuel lines and new high pressure rubber line. The small length of rubber fuel line has never kinked. A long screwdriver keeps your hand from blocking your view. Just use a small led light to inspect your work and remember the proper type of fuel clamps. I also put a touch of MMO in the line so it slips onto the tank easily.
[/quote]


Can you hook it up through the small round hole, from under the car?
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mepstein
post Feb 27 2020, 09:10 PM
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[quote name='stevegm' date='Feb 27 2020, 10:06 PM' post='2789824']
[quote name='mepstein' date='Feb 27 2020, 09:58 PM' post='2789819']
[quote name='Jamie' date='Feb 27 2020, 09:52 PM' post='2789817']
[quote name='poorsche914' date='Feb 27 2020, 06:38 PM' post='2789812']before s my question - if I use a very short line, can I access it to hook it up, through the round hole beneath the tank (photo below), from beneath the car? [/quote]
I don't think so, at least not easily.
Shorten the current line a bit if needed and lower the tank so it doesn't get kinked. Maybe access the fuel line through the hole to help position it. (IMG:style_emoticons/default/confused24.gif)

EDIT: well, maybe you can??? I never could (IMG:style_emoticons/default/dry.gif)
steve
(IMG:style_emoticons/default/driving.gif)
[/quote]
It really helps to have a longer fuel line so that you can form a complete loop between tank and supply line into tunnel. There is then less chance of forming a kink that will cut off supply from tank. (IMG:style_emoticons/default/barf.gif) I eliminated the notoriously troublesome sock filter in the tank, and have a filter installed before pump up front and another filter in the engine compartment.
[/quote]

I disagree. All my cars were refitted with Tangerine racing SS fuel lines and new high pressure rubber line. The small length of rubber fuel line has never kinked. A long screwdriver keeps your hand from blocking your view. Just use a small led light to inspect your work and remember the proper type of fuel clamps. I also put a touch of MMO in the line so it slips onto the tank easily.
[/quote]


Can you hook it up through the small round hole, from under the car?
[/quote]
yes
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stevegm
post Feb 27 2020, 09:16 PM
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The kink doesn’t seem to be the only problem. Gas isn’t flowing out of the bottom of the tank very freely. Is behind this line fitting where the fuel “sock” is?


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iankarr
post Feb 27 2020, 09:40 PM
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Yes, the fuel sock is behind that fitting. I think the easiest way to prevent kinking is to coil the line before you hook it up. IIRC the ideal length is 21 or 22 inches. Details and how-to towards the end of the fuel line video in my signature below...
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Mark Henry
post Feb 28 2020, 12:29 PM
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I've found giving the hose a twist a certain way it coils in a nice loop when the tank is installed. I can then get the screwdriver up there to make a fine adjustment if needed. You have to make sure you orentate the clamps the right way so you can reach them through the window.
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