Injectors Leaking

[beowulf]

Last summer I had gotten a set of four GTD nozzles from kermatdi to install in my 1.6L NA diesel Rabbit. I had sent them off to Duane to be installed in injectors and pop tested.

Well, I finally got around to installing the injectors recently and everything seemed to go smoothly with removing the old injectors and installing the new ones.  (My procedure was loosen the nuts on the pump end, loosen the nuts on the injector end, remove injector lines, then remove the injectors.  Installation was reverse of removal.) However, once I had tightened everything back up there was diesel bubbling from the #4 injector (third injector when counting from the timing belt side of the engine and moving to the right).  I loosened everything and tightened it up again, but the injector still leaked.  I tightened the nuts on the steel injector lines until I could feel they wouldn't tighten anymore and didn't try to get a lot of torquing or levering when tightening them.

So, I ordered new steel injector lines (thinking maybe the original injector lines were worn out).  After installing the new injector lines #2 and #4 are still leaking fuel out of the junction between the injector and the steel line now.  I've loosened and re-tightened them several times with no change.

What am I missing here?  Is there some sort of gasket or seal I'm supposed to be installing to help the nut seal?  Could it be that the GTD nozzle pops at too high of a pressure for the stock steel lines?  I've done an injector swap on my 98 Jetta and everything went back together without a problem, so I wasn't expecting to run into any problems on my Rabbit, but I can't seem to get the steel lines to seal onto the injectors.  Any advice will be appreciated.  Thanks.

[Rabbit TD]

The injection lines can handle MUCH higher pressure than any VW injectors without leaking.  No gasket.  Remove the lines and inspect both the lines and the injector tops for any burs or irregular depressions in the metal.  When installing the lines be sure to push the line squarely onto the injector and then turn the nut on finger tight.  If instead you have been just wrenching on the nuts to pull the lines into place then you have likely deformed the ends of the lines from not having them aligned properly when tightening.

I did that same thing myself a good while back, luckily I had a couple other lines on hand.  They have to be straight first before tightening up.  Don't forget if you adjust the pump timing to loosen them a little before you move the pump and then tighten back up after it's retimed, it takes the stress off the lines and also makes timing a little easier.

[Vincent Waldon]

Always hard to tell over the interweb, but sometimes folks think fuel is bubbling down the side of the injector from the hard lines when it's actually coming from the rubber return lines... they gradually fail over time *and* sometimes get bumped/prodded/jarred while working on the hardlines, causing them to spring a leak that didn't exist before.

In this case it sounds like you can clearly see where the fuel is coming from, but I thought I'd mention it as a possibility for future searchers.

[jtanguay]

yea the cloth fuel line is pretty weak and i suggest using more than is needed.  my car developed a leak at the point where the return line hooks into the barbed return on the pump.  so i clipped the end and hooked it back up, and within less than a minute of running it did it again!  but the hose was pretty stretched, so next time i'll put a lot of slack into it.

[beowulf]

Thanks for the comments everyone.  I did hand tighten the hard line nuts before tightening with the wrench, but I am going to carefully follow the suggestions here.

I figure it can't hurt to replace the cloth/rubber fuel return lines, as well, since they could be a source of leakage.  Any suggestions on where can I order replacement hose?  Thanks.

[mtnbob]

I got mine from Napa auto parts. They stock it as mercedes diesel fuel line hose, at least that's what they told me