[First opel 1981]

I've replaced the lines To the FI on my 2.4 Targa and am planning on going to metal lines. What Diameter are is suggested. I have a lot of 1/4 " from a carb job but think the FI may require bigger diameter. Also I never replaced the return line to the tank...I did disconnect it and it flowed well but I'm not sure if It should be replaced soon.

1/4" ID should be fine.
Your FI has a lot more pressure but no extra flow. We are talking a gallon every 20 minutes on a bad day. If you can't get that much gasoline through 20 feet of 1/4" hose at a 50+ PSI then you have bigger problems.

 

[crliwa]

Confused

After reading this thread a couple of times I am now leaning towards Charles recommendation of the barracuda ? FI lines..... but WHAT CONNECTORS DO YOU USE?
I currently have the fuel line from the tank with the Ethenol rated FI line from O'Reilly. I believe it is 5/16 or 3/8".

I began to run the 1/4" steel tubing forward from there but with all the bends (after the U turn out of my fuel filter that I have after the Electric fuel pump) I am rethinking this. I do not have a tubing bender and used a can to wrap the tubing around to make the first bend ...each successive bend is more difficult. I raised the car on jackstands so I have 14" clearance but that makes doing this a little more difficult than if I was using a lift.

Any/All additional info is appreciated

 

[slracer]

After reading this thread a couple of times I am now leaning towards Charles recommendation of the barracuda ? FI lines..... but WHAT CONNECTORS DO YOU USE?
I currently have the fuel line from the tank with the Ethenol rated FI line from O'Reilly. I believe it is 5/16 or 3/8".

I began to run the 1/4" steel tubing forward from there but with all the bends (after the U turn out of my fuel filter that I have after the Electric fuel pump) I am rethinking this. I do not have a tubing bender and used a can to wrap the tubing around to make the first bend ...each successive bend is more difficult. I raised the car on jackstands so I have 14" clearance but that makes doing this a little more difficult than if I was using a lift.

Any/All additional info is appreciated

Craig, Have you thought about one of these? https://www.harborfreight.com/tubing-bender-3755.html

Doug

 

[First opel 1981]

Craig, Have you thought about one of these? https://www.harborfreight.com/tubing-bender-3755.html

Doug

I was going to suggest that. I have two of them, myself, that I bought for the sole purpose of bending the fuel line from the fuel pump to the carb.
I have since rethought that and have been running a rubber hose.

For the main line from the tank. The bends aren't that critical and just need to get into the hangers on the bottom of the car. My son did his in less than 15 minutes with about the same 14" clearance that was mentioned above.

Remember that there has to be a flexible connector between the body line and the engine. Engine vibrations will fatigue the steel fuel line otherwise.

 

[Autoholic]

The type of fitting to use is a hose barb. You just push the hose over the barbed fitting and then clamp it down with any sort of clamp, there are various types of clamps that can be used. A hose barb can be used directly with parts like the fuel pump or used to go from hard line to flex line, like Gates Barricade. These are rather cheap fittings, usually made of brass.

If you do use hardline, you will need to bend it with a tubing bender and flare the ends for fittings. Nothing worth doing correctly is easy.

 

[Will I. Finish]

There was a lot of very good and useful information contained within this thread, however the problem that I continue to have is finding a black rubber, black nylon flexible fuel line, like the one that came with the car, to properly fit the metal gas tubing. Since the black flexible fuel line is fiber reinforced it is impossible to get the hose over the metal tube line to get that really snug fit. I am using 3/8 black fuel line that just slips over the metal tubing without giving you that really snug fit and I have had leaks twice when i thought I had it sufficiently clamped the connections with a standard radiator style clamp. Anything smaller, black fuel line, will only go over the steel tube up to but no more than about a 1/4 of an inch and then try to get it on the other end that does not allow you twist and turn it like the first end that has already been installed. In any regard my results with anything smaller than 3/8 just does not work and I am not happy with the fit of the 3/8. Do I just need to widen my search for a slightly smaller black line to fit over the steel line as I have been unable to find it at any of the major auto supply stores, that includes, O'Reilly, Auto Zone, Napa, and Advanced auto. Is there another source that I should be using? I have some left over clear line that I got from OGTS for the run from the tank to, just before the fuel pump that I think may work to give me that snug fit that I am looking for. Would it be acceptable to use that to replace the two small sections of the black line at the carb. See picture below.
I know this is a small problem and have a feeling there is an easy answer. I have by chance, discovered a leak right at the Carburetor, just by chance - today being one of them, right over the manifold, scary - I just want to make sure it is done right. I tightened up the connection, went for a drive, but just don't feel comfortable. Thanks. Carl

 

[G.v.Mainberg]

I am pretty sure that the steel lines have an outside diameter of 8mm, so a 5/16" inside dia rubber fuel line will fit perfectly ofer it.

Dieter

 

[kwschumm]

If you can find metric fuel lines 9mm is slightly smaller than 3/8.

 

[First opel 1981]

Rubber Fuel Line Gas Hose 5/16" Id X 1 Foot Sold By Foot Return Vapor Usa | eBay

Find many great new & used options and get the best deals for Rubber Fuel Line Gas Hose 5/16" Id X 1 Foot Sold By Foot Return Vapor Usa at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[G.v.Mainberg]

If you can find metric fuel lines 9mm is slightly smaller than 3/8.

While you are right with your statement, I do not believe there is any such thing as a 9mm fuel line.
6mm - 1/4"
8mm - 5/16"
10mm - 3/8"
12mm - 1/2"

Dieter

 

[kwschumm]

While you are right with your statement, I do not believe there is any such thing as a 9mm fuel line.
6mm - 1/4"
8mm - 5/16"
10mm - 3/8"
12mm - 1/2"

Dieter

Here's one.

RH9 - Braided Hose 9mm [N203591] - $12.79 : Bel-Metric, Metric Hardware, Metric Fasteners, Metric Bolts, Metric Nuts & Time-Sert Thread Repair

Bel-Metric RH9 - Braided Hose 9mm [N203591] - 9mm CONTINENTAL vacuum, fuel, etc. German OEM ID 9.0mm, OD 14.0mm Hoses are cut off a continuous spool, charged per meter Roll length (longest continuous cut) is 5 meters. CONTINENTAL # N203591

www.belmetric.com

 

[kwilford]

.... and I am now replacing the black nylon fuel line under the car...

Umm, the nylon fuel line is not black. It is kinda' translucent beige.

The fuel tank vapour vent line is black. It may also be nylon, but it is considerably thinner walled. DO NOT USE THAT AS A FUEL LINE!!!!

Hmm, I just noticed that this thread was resurrected from 3 years ago. Whatever, do not use the black line as the fuel line!

 

[Manta Rallier]

Will I., there are better hose clamps that are easily found too. Go and ask for hose clamps for fuel injection systems. The have a smoother band that overlaps itself and clamps more evenly around the hose.

You may want to buy and use a compression fitting on the end of your main fuel line that adapts to a 5/16" barbed fitting to make this all easier. There are some made explicilty for fuel use, but since this is a low pressure system, probably any compression adapter will work fine. Some such adapters are for nylon hose and I don't think those sizes are quite right for 5/16" rubber hose.

I personally would eliminate the short right angle piece, or replace it; that looks like a headache to get the hoses onto.

 

[opelbits]

Will I., there are better hose clamps that are easily found too. Go and ask for hose clamps for fuel injection systems. The have a smoother band that overlaps itself and clamps more evenly around the hose.

You may want to buy and use a compression fitting on the end of your main fuel line that adapts to a 5/16" barbed fitting to make this all easier. There are some made explicilty for fuel use, but since this is a low pressure system, probably any compression adapter will work fine. Some such adapters are for nylon hose and I don't think those sizes are quite right for 5/16" rubber hose.

I personally would eliminate the short right angle piece, or replace it; that looks like a headache to get the hoses onto.

Something like these...nice German quality. Used them a lot working on Alfas. Also, when clamping to any line that is not barbed or have a 'ring' in it or even the old nylon line, I'll use two clamps for less clamping force but more clamping area.

Zebra Power Hose Clamp Band 9 | Zebra | Clamps | Service and Repair Parts | Wurth USA

 

[Manta Rallier]

Yep, something like those. You can get such clamps at any auto parts store nowadays; just ask for hose clamps for fuel injection systems.

 

[opelbits]

One thing that was really nice about the Zebras, we had a nice flex shaft nut driver about 6 or 8 inches long. It didn't slip off and you could get around things.

 

[Will I. Finish]

Found the fuel line and installed today. Got rid of the extra piece of metal fuel line, see previous picture - Purchased 2 fuel injection clamps. project complete. See Picture. Thanks for all of your comments. Carl

 

[Manta Rallier]

Leak free?

 

[Will I. Finish]

Leak free?

YES, the new fuel line which now snugly fits the metal fuel line in addition to the fuel injection clamps, that you recommended, did the trick - I feel really confident that I have a situation that is going to work for the long term. Think that heat from the engine had a hand in the problem. I also tightened up the connections from the pump to the metal line and also the connection from the main fuel line to the pump. All secured. Thanks.................Carl

 

[thevisualedge]

1. How do I properly connect the short sections of rubber hose back at the tank and again at the fuel pump to the long nylon run in-between? It seems the factory or previous owner just slipped them over the nylon and hose clamped it. Is this correct and/or safe? Seems like it could slip off. I was hoping for some kind of compression fitting over the nylon that goes to a barb to connect the rubber hose, but can't seem to find anything. What is the right way to do this? I am okay with the slip fit and hose clamp if it is factory and safe. I'm using Gates Barricade carb hose.

I've been spending the last several days trying to figure out this exact issue for my VW Corrado VR6. A Google search for "how to connect rubber nose to a nylon fuel line" brought me to this thread! My car came from the factory with single-use clamps joining the rubber fuel hoses at the ends of nylon fuel lines. I've been scouring the net looking for a way to re-create a rock-solid, leak-proof connection, whether it be compression fitting, barbs, etc.

There seem to be connectors for nylon-to-nylon, nylon-to-steel, etc. etc., but I was having a hell of a time finding a solution for rubber-to-nylon.

I think I finally landed on the perfect answer, and it's embarrassingly simple:

Get a barbed in-line reducer (you'll need to specify it for your own hose sizes, obviously). Pair those with proper fuel line hose clamps (the T-bolt style clamps, NOT the crappy worm-drive clamps), and you should be good to go with a connection as good as new.