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habdala
02-01-2016, 05:50 PM
Hi there!

A few months ago I opened the injector cover and found some black death on injectors 2 and 3. I proceeded to order the screws and copper washers so I can re-seat the bad injectors so after a few months I order the parts needed and today was a good day here in the NOVA area to tackle the job so I proceeded to clean the carbon and to my surprise it was crystallized and very easy to remove I also notice that the top of the injectors where also coated with a very thin layer of carbon so my question is: Can the top return line T connector be leaking? and do they have O rings cus I didn't see any on the ones I removed.

https://drive.google.com/drive/folders/0B_tdBuoSCPkzOHJwTEdfTDBUNDQ


Thank you!

NelsonSprinter
02-02-2016, 09:07 PM
I'm not a mechanic so don't know for sure, but when I changed my injectors I also could not see any O-rings on the top connectors
The thin carbon on the injectors' top is probably from the escaping gas condensing . The dry black death probably means the leak is old and re-sealed itself and crystallized from a long drying

Aqua Puttana
02-02-2016, 10:40 PM
If the reference to no O-rings is regarding the one end "L" and 4 ea. "T" fuel return connectors held by the ss clips, there is definitely an O-ring. It is so close fitting in the plastic that the black "ring seal" looks like part of the plastic assembly.

Under normal operation there is not enough heat in the injector gallery to burn leaked fuel to carbon. It is the escaping exhaust gases and the heat of compression which causes the black lava.

If there was enough heat in the injector gallery to break diesel fuel down into the basic carbon component then that same heat would melt the plastic electrical connectors and wire insulation.

:2cents: vic

MillionMileSprinter
02-03-2016, 03:49 AM
Vic is correct: there most definitely are rubber o rings on the plastic fuel return line that runs across the tops of the injectors. Yours may be so old and hard that they appear to be part of the plastic fitting, but they are not.
Also, if you've got "black death", then its from the copper injector seals in-between the injector and the head, no matter if the " lava" is easy to remove or not. And in my experience with "black death", if you get it before it gets really bad, its not too hard to scrape off most of it. You do, however, need to replace the seal. It will come back sooner or later.
Also, I have to say, the term " black death" is really a misnomer. There's no catastrophic engine failure. You can very likely re use the injector. It's just a bad seal that needs replacing after you clean off the sealing surface inside the injector bore. There are posts here on the forum explaining different methods of doing this. You also need to replace the injector hold down bolt and use a torque wrench to properly re-tighten everything down. It's not particularly difficult as long as nothing goes wrong. Sorry, I'll get off my soapbox now.