injector return hose popped off

[vmb]

Well, just changed the fuel filter on my 86 jetta turbodiesel, drove it around last night and noticed a little fuel on one of the injectors, first time seeing this. Today, I drove it around some more and suddenly started smelling fuel. Decided to turn around and head home as that's usually not a good thing, right?
Got into the neighborhood and started hearing the alternator belt squealing obnoxiously, pulled into the driveway and sure enough there was a long trail of fuel the whole way.
Popped open the hood and one of those return hoses between the injectors had popped clear off the injector. It hadn't done that before with the old filter and showed no signs of leaking. Mind you, the old filter was who knows how old, I had just got the car recently. Sprayed down the engine bay as best as I could, trying to get as much of the fuel out and especially off of the rubber hoses and plastics.
Dug around the internet and around here, and so far hadn't found anything about this, so I'm at a bit of a loss. My guess is the new filter allows better flow of fuel and those lines are old and need replaced. Thought they do seem to sit on the outlets fine...
Might also try zip-tying those hoses down.
Any ideas as to what might have caused this?

[sgnimj96]

Should be very low pressure on the return lines regardless of the fuel filter condition.
The correct size tubing should be fine without any clamps or zip ties.    Replace 'em if they're old.


(quote from another IDI forum)
"One of the things that can cause too much pressure inside of the Injector is if Combustion Gasses are getting into it.
Poor lapping of the Parts or the Injector halves not being torqued enough can cause that.
Heat Shield upside down?
You could try swapping the Position of the Injector and see if the problem follows the Injector."

[vmb]

Should be very low pressure on the return lines regardless of the fuel filter condition.
The correct size tubing should be fine without any clamps or zip ties.    Replace 'em if they're old.


(quote from another IDI forum)
"One of the things that can cause too much pressure inside of the Injector is if Combustion Gasses are getting into it.
Poor lapping of the Parts or the Injector halves not being torqued enough can cause that.
Heat Shield upside down?
You could try swapping the Position of the Injector and see if the problem follows the Injector."

I figured replacing the lines first would be a logical first step. Figured I'd order some fuel line hose from partsplace this week anyway, or at least see what I can find around here. If not that, then I'll check the injector itself. It only did it on one, so it might just be any one of those things mentioned.
It just find it odd that it started doing it after replacing the fuel filter...
Any other causes for too much pressure in the injectors?

[ORCoaster]

Rather than place an order from Parts Place just go hit the neighborhood motorcycle shop.  They generally have that size clear tubing on their engines.  And you don' t pay shipping. 

If the maintenance was lacking those hoses might just have finally given up the ghost.  Until you get new hoses you can snip off 1/4 inch and replace on the nipple.  Be sure to push down and give a slight tug up on it.  That helps to tighten then on the nipple.

[rumbling_caddy]

I had had the same leaky return lines problem after purting my 1.6td back together recently.  Good tip on the motorcycle shops.  I hit up a bunch of auto parts store before finding something that would work. Still not happy with the material so I ordered some 1/8" black silicone hose from Amazon

[vmb]

Looks like I'm going to motorcycle shops tomorrow.
Hopefully it'll just be the line.
1/8th in is correct, yes?

[libbydiesel]

Changing the fuel filter had nothing at all to do with the return line popping off unless you bumped the line while changing the filter.

1/8" ID is fine.

[vmb]

Yea that might have been what happened while moving the lines around. Main return line or the line going to the pump might have knocked it loose.
Whatever the case, breaking out the pressure washer and gonna look for those lines

Thanks guys.


Just an update. Cut the line that was on there already. Seems to be sealed a lot better. I got some 1/8in fuel line just in case though. They don't seem as tight on the injector as the others though, so not sure what's up with that. The 1/8in line seems to fits a lot better, but I might just see how it does.

[vmb]

Don't mean to bump my thread, but the issue came up again.
I swapped all my fuel lines to tygon lines, and now the #3 injector had a hose come loose and off. #1 has some leaking around it, replaced the line again. Staring to think there's too much pressure on the return line. Any cause for this? I know someone mentioned it earlier. Bad venting in the fuel tank maybe?

[libbydiesel]

The only cause for excessive pressure in hoses between the injectors would be a restriction in the return banjo or line to the tank. 

[vmb]

So, what you're saying is, I'm probably overthinking this.

[air-cooled or diesel]

i gave up with the clear lines, i ll use them to see if i have a problem, the one inj (#3) kept on leaking for me. put back on the good black lines. forget what are they 5mm? as for if you feel you have a restriction,,one way to try to flush it out is with lubro-moloy, or sea foam, for concentrate i put in 3/4 tank. you dont need it this concentrated much. (too often).

[sgnimj96]

The only cause for excessive pressure in hoses between the injectors would be a restriction in the return banjo or line to the tank. 

Try blowing (compressed air) through the return line.    Unlikely there is any trash in the return line but the metal tubing or rubber hoses could be damaged. 
The injector return lines first have to pass through the banjo fitting on the IP out bolt,  unlikely it has any blockage but you can easily (but carefully) take it off and look at it.

[libbydiesel]

To be clear, the fuel from the injectors does not re-enter the OUT bolt.  It will flow into the banjo fitting that is around the bolt and then down the return line.  I did see one 1.6 that had a restriction on the line back to the tank.  It kept blowing seals on the injection pump and the hoses on the injectors leaked.

I've been using the clear tygothane for several years on multiple vehicles and have found it lasts longer and is less prone to leakage than the actual VW cloth braided black hose.  The easy diagnosis of air infiltration is just a bonus. 

[air-cooled or diesel]

the banjo fitting can take up to what is it? 3 copper washers, make sure you have a set before you open it up, they can be hard to find, of course its easiest to take a washer to the store after you free them up, but at least make sure you know you can get a set.