CIS Fuel Lines

[patkeefe]

Hi all:
I know we have been over all of this before, but has anyone figured out a source for new CIS fuel lines? I'm about to pick up a roll of nylon fuel tubing and try that. I predict it will be hellish to get the line over the little fittings. Wish I had some steel lines...

TIA.
Pat

[HarryD]

A seach for posts by Jim Sims and the term nylon will find what you need. Read carefully, there have been some issues reported.

A few links to get you started:

Alternate CIS fuel injector hose/tubing?

Start-up Injector Fuel line leak

[patkeefe]

Thanks, Harry

[kimlangley7]

I had my plastic fuel CIS injector lines [80 SC] replaced with the metal versions 84+? .. Just scared of plastic >> carrying fuel under pressure

Ping the WTB here on Pelican > people are constantly selling all sorts of stuff

[GBStu]

Pat,

Take a look at the end of this thread:

CIS misfire

It took me over a year to figure out the new nylon fuel lines were causing a low rpm misfire.

Good luck, Stu

PS, I bought another set of plastic OEM lines and pieced togther a new set with my originals.

[HarryD]

Stu,

Thanks for speaking up. I know there have been issues. I am wondering if it is mostly limited to the lines between the fuel distributor and the injector. I would think the other lines which should not pulse as readily as the individual injector lines.

[patkeefe]

Stu
Thanks. The explanation in the link you posted sounds plausible, especially regarding the fuel volume per open cycle. My original factory lines are still intact, except for the return line, which doesn't have the same issues as the injector lines. I have noticed that the factory lines are quite thick walled, and I would imagine these will likely not have much of the effect described in conjunction with your problem.

I suppose I'll just live with the old lines until I can come up with a better solution, or find some steel lines and hardware.

Thanks to all for the help on this.

Pat

[evill]

Pat, when I did a custom CIS set up on my old 914, I had a hydraulic shop make my lines. They used the fittings from the old lines and pressed them into the new lines, which were a flexible plastic with a nice rubber sleeve on the outside. They also put nice crimp sleeves on the ends. I don't remember who did them, but it was inexpensive, less than $10 per line. Look in the phone book and call around.

Ed

[patkeefe]

Thanks for the info, Ed. I thought about swedging some lines like we used to do on the hydraulics in aircraft, if I could find banjo fittings. But, your idea is pretty solid. I'll call around.
Pat

[DohertyCM]

I have the same issue, i think that I am going to get the lines from Aircraft Spruce and Specialty Co. an aircraft parts supplier.
They seem to have hose that looks like the CIS hose and will hold 3000 psi...HOW THAT FOR FUEL PRESSURE!... But I think it will work...6 feet at $4.45 a foot..

I just have to make sure that I get the right size..

[GBStu]

Harry,
The issue was with the nylon tubing between the fuel distributor and the injectors. I have used the nylon tubing between the WUR and distributor without a problem.
Thanks, Stu

[tom1394racing]

I have a set of NOS CIS fuel lines for an SC that are available for sale.

PM me if anyone needs these.

[klaucke]

I found it was really hard to push the the banjo fitting into the OEM plastic line when I trimmed one of mine (shortened it a small amount to get rid of a kink). I found the easiest way to do it is to hold the line in a small 3-jaw chuck from a lathe, and push the nipple in lightly with an arbor press. You surely can't push them in by hand w/ old, stiff lines.

[HarryD]

UPDATE

I found this web site: http://www.dssales.net/CIS.html

I note that they state for Injector lines, you need to use the 2 mm ID material as lager sizes cause pulsing.