Start-up Injector Fuel line leak

[HarryD]

Today while futzing around to fix my non-woking brake light, I smelled fuel. On unvestigation, i appear to have a hairline crack on my start-up injector fuel line where it meets the CIS Fuel distributor.

Using my mirror, it looks like the fuel line is shrunk on to the injector body and the other end has a fitting to connect to the fuel distributor. Looking at my PET Catalog, it looks like the startup inector comes with a new fuel line. Is this correct?

Do I need to remvoe the engine to access this part, or can I remove the air box and U-shaped air path from my CIS engine and do it while the engine is in the car?

[HarryD]

It's great to ask a question that seems to stump everyone. I just do not like being that person.

Anyone BTDT?

[vash]

harry, it is actually amazing how much room there is once you get the top of the CIS out. personally, i have taken the line from the fuel distributor, so i know that end is managable with the motor in. i bet the hell is the cold start valve side. if it was me, i would try it. get that alien head shaped thing off and go.

sorry, i dont know if the line comes with a new CSV.

[Jim Sims]

Harry, I do believe you are seeing a leak in the hard nylon line to the fuel control valve not a leak in the line to the cold start valve (CSV). See the below images. The fuel control valve has the dot of yellow paint on it in the following images.



FRONT TOP of 73.5T CIS




73.5T CIS Fuel Control Valve (Control Pressure Regulator)




73.5T CIS Cold Start Valve (CSV)




1973.5T CIS Parts Diagram

The Fuel Control Regulator (Control Pressure Regulator) is shown coming (item number 43 in the above parts diagram) with the hard nylon fuel line and the banjo fitting at the fuel distibutor end; it is still available (911.110.916.00) for $242.80. I believe the Fuel Control Regulator is a part used only on the 1973.5T and perhaps on some of the 1974's. The parts catalog also lists the fuel line alone (911.110.096.00) and it apparently also is still available for $22.17. I recommend removing the Fuel Control Regulator and line from the car and replacing the line on a bench top. Usually the old nylon lines are burned off the barbs of the fittings but in this case I don't think you can do that. Perhaps you can get it off by futher splitting open the leaking crack; do not use metal tools as the slightest nick on the barb is likely to cause a fuel leak making the old Fuel Control Regulator useless.

The line to the CSV is actually externally braided hose.

Cheers, Jim

[Jim Sims]

See: CIS W.U.R. 73 1/2 superceded

Information about installing new nylon fuel line in above thread. Jim

[HarryD]

Jim

Thanks for speaking up. You appear to be correct. Thanks for the clarification.

Is this something I can remove without pulling the engine? I figure i would need to remove the duct on the CIS but, hopefully i would have enough room to access the valve.

One other idea. since the leak is on the banjo fitting end, would it make sence to use some type of coupler to leave the tubing alone at the regulator?

I can see cutting off the old line, but I am having troble visualizing the connectors. You wouldn't have a picture or is it very obvious once you see it?

[Jim Sims]

I believe if you remove the boot (duct) at the top and use a mirror as a work aid you can disconnect the fuel control regulator and the line with the engine in place. I do not know where to get a splice fitting (barbs on both sides) for the hard nylon fuel line so I don't know if you can follow your splice plan. However, if there is enough slack in the existing nylon line you could cut the line as close as possible to the barbs on the banjo fitting. Then burn off the small bit of remaining nylon line on the banjo fitting and reinstall the banjo fitting on the remaining line using the Baum tool or substitute (per above thread). I would only try this on a bench top; not on the engine. I have a spare barbed banjo fitting but do not have my digital camera with me tonight. I'll try to capture an image tomorrow and post it. If I had to melt the nylon line off the fuel control regulator barb I would try and apply heat in a precision manner using a soldering iron; never done it though. Jim

[HarryD]

Jim,

At $242 for the assembly, I guess it is worth a try to repair just the line.

Have you had any experience/knowledge using a Swagelock tubing coupler on these lines. I think I'll call them on Monday and see what they think.

As an aside, I noticed that the power connector for my Startup injector appears to have fallen off as well. Looks like two little repairs when I am back there.

[Jim Sims]

No experience using the Swagelok fittings with nylon tubing. I usually use the the fittings with metal tubing. The issue may be finding the correct size to match the tubing OD and getting the ferrules to seal on the nylon. There are also "medium" pressure fittings made specifically for plastic tubing (we use them on the tubing for the pressurized air lines controlling high voltage equipment which must stay electically isolated). The questions are whether the plastic tubing and fittings are rated for hot gasoline service and the pressures encountered (100 psi or so). Let's us know what you find out. Jim

[HarryD]

Jim,

You may be correct in that they may not make the correct sizes. I have used them on pressurized liquid lines and they seem to hold but the lines were SS not nylon. I hope they did some reseach at Corp.

This afternoon I pulled the air duct on my CIS unit and I can see the two 5 mm cheese head screws that hold the unit in place. I think I should be able to remove it once I get my contortionist skills back.

[HarryD]

Jim,

I looked at your thread on installing Nylon lines and I guess I need some 5 mm material.

Since I couldn't locate the needed specail hose holding tool I made a "substitute". Perhaps John Walker knows where the official tool can be obtained. I'd like to buy one.

www.mcmaster.com

The line is black nylon 11, this is the same material as the old line. The temperature, pressure and chemical rating information may be found on the McMaster-Carr web site. You can order on-line with a credit card.

3mm ID x 5mm OD: stk number 50405K12@$0.26/ft 100ft coil (I believe this is the size to the WUR)

4mm ID x 6mm OD; stk number 50405K13@$0.31/ft by the ft. (this is the fuel distributor to injector size)

6mm ID x 8mm OD; stk number 50405K14@$0.43/ft by the ft. (this is size from fuel filter to distributor if this line is plastic on your car)

I also ordered the following collars to make the "substitution" installation tools:

Metric One-Piece Clamp-On Collar Black Oxide Finish, 5mm bore, 16 mm OD, 9mm Width; stk number 57445K22@$2.19ea

Metric One-Piece Clamp-On Collar Black Oxide Finish, 6mm bore, 18mm OD, 9mm Width; stk number 57445K23@$2.29ea

Metric One-Piece Clamp-On Collar Black oxide Finish, 8mm bore, 24 mm OD, 9mm Width; stk number 57445K24@$2.24ea

Old line is burned off fittings (per the shop manual?!). You could proabably cut it off your old WUR if you have enough line slack. Slit the collar at the narrow neck with a dremel abrasive disk or a fine hacksaw so each breaks into two pieces. Wrap a bit of fine sand paper (for enhanced friction) around fuel line then put collar around sandpaper and line and tighten set screw. Make sure only a small portion of the nylon line extends out of collar. Nylon may be softened by wet heat; put end of tubing in boiling water. Dry heat will make it shrink. Clamp the collar with vise grips (the set screw doesn't privide enough clamping); then insert tubing onto end of barbed fitting and tap the side of the vise grips with a soft faced hammer to drive on. WUR needs to be clamped/arranged so that you can push or drive on the tubing. One can't have too much of the tubing protruding from the collar (otherwise it will buckle) so the collar may have to be moved backup the tubing a couple of times as the tubing is driven on. Buy extra line to practice with, you'll need it and its cheap.
Cheers.
Jim

One question, I figure you are using the collar to drive the softened tubing onto the fitting barb. If I slice the collar apart, how does the set screw hold it together?

[Jim Sims]

"Clamp the collar with vise grips (the set screw doesn't provide enough clamping);" Or use the jaws of a vise to clamp the collar onto the tubing and a soft faced hammer to tap the banjo fitting down into the nylon line. Jim

[azasadny]

Jim,
I just did a partial engine drop to replace all fuel and vacuum lines, as well as rear shocks and motor mounts. I dropped the engine about 18" and had plenty of room. Good luck! I used the hoses from PP and clamps from McMaster Carr and all went well!

[HarryD]

Originally posted by Jim Sims
"Clamp the collar with vise grips (the set screw doesn't privide enough clamping);" Or use the jaws of a vise to clamp the collar onto the tubing and a soft faced hammer to tap the banjo fitting down into the nylon line. Jim

Jim,

Thanks. Sometimes I am a bit slow on the uptake. Looks like I will need some 5 mm tubing and a few clamps.

[HarryD]

Originally posted by Jim Sims
No experience using the Swagelok fittings with nylon tubing. I usually use the the fittings with metal tubing. The issue may be finding the correct size to match the tubing OD and getting the ferrules to seal on the nylon. There are also "medium" pressure fittings made specifically for plastic tubing (we use them on the tubing for the pressurized air lines controlling high voltage equipment which must stay electically isolated). The questions are whether the plastic tubing and fittings are rated for hot gasoline service and the pressures encountered (100 psi or so). Let's us know what you find out. Jim

FWIW, I have used the Swagelok fittings with teflon tubing. They make a special sleeved ferrule for the application but I am not sure of the rated pressures. Like I said, a call to Swagelok would help but the cost of their fittings is very high. Your press-on method is much more cost effective, as long as you can work with the fittings at each end.

[HarryD]

Well, it's 2 am and I just put my car back together again. Jim's procedure to repair the nylon lines works.

If you plan on making your own lines, plan to practice a bit. I am also glad a bought a few collars as I destroyed one while I was learning.

Bottom line, I ended up spending about $15 and 3 hours to replace the leaking line. This is a definate improvement over buying the $242 assembly or the $22 nylon line plus find a way to attach to the valve barb.

THANKS JIM! If I am ever in the same place as you, I owe you one!

[HarryD]

Originally posted by Jim Sims
No experience using the Swagelok fittings with nylon tubing. I usually use the the fittings with metal tubing. The issue may be finding the correct size to match the tubing OD and getting the ferrules to seal on the nylon. There are also "medium" pressure fittings made specifically for plastic tubing (we use them on the tubing for the pressurized air lines controlling high voltage equipment which must stay electically isolated). The questions are whether the plastic tubing and fittings are rated for hot gasoline service and the pressures encountered (100 psi or so). Let's us know what you find out. Jim

Jim,

I chatted with the Swagelok guy. Their fittings "should" work" but we may need to cut a groove to use the plastic ferrules they offer in place of the more familiar metal ones. FWIW, 5 mm OD tubing is a non-standard size for them but 6 and 8mm are available. Probably the biggest drawback is cost. A SS unit swill cost $30+/ea and a brass one not much less. You can try the PFA or Polypro ones but they are more tricky to work with and they creep.

[Jim Sims]

Congatulations on a successful repair. What technique/method did you use to remove the nylon line off the fuel control valve barb? Jim

[HarryD]

Originally posted by Jim Sims
Congatulations on a successful repair. What technique/method did you use to remove the nylon line off the fuel control valve barb? Jim

I used my low wattage soldering iron and burned a line of holes into the nylon and tugged gently. I saw that suggestion in the Shop manuals.

[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.