Fuel leak off injector - can't pin it down.

[WarWagon]

Tracking a leak back is sometimes fun. This one is from the #2 injector, running down the turbo oil drain tube and looking like a leak at the rubber coupler on the oil drain tube.

Rebuilt injectors. Does not leak when up to temperature. Will leak when cold running or sitting.

Paper towel shoved between heat shield indicates injector is the source of the fuel leak.

I have trimmed the return lines and that did not fix it. Cut 1/4" on each line at the injector. Return lines have ~30K on them and 1 year old. Reused for this injector set.

I simply can not tell if it is the injector body or the return lines leaking at the injector.

:nonod: So now what?

 

[Turbine Doc]

Clean suspect area with acetone or alcohol so tape can stick to it, wrap paper towel around the body tape it down with painters tape or similar or a twist of .032 safety wire, then aluminum foil around that which will keep air blowing around the engine bay from migrating to other places in bay making it hard to locate the source.

Same with your jumper lines, what I've found on older lines with the cloth braid you get weepage past the rubber but the cloth over-braid hides it when the whole line becomes saturated, go for a run and then see which is leaking.

I learned this tip back in my aero GT days where a drop of synthetic engine oil weeping looks like gallons of oil are leaking, tampons and feminine napkins for large leaks are handy in this role as well but you get some odd looks from folks when you tell them what you are doing with them departing from their intended purpose

 

[bk95td]

If the injector halfs mating surfaces weren't trued good enough they will leak. Guess how I know that. I've also had a cracked injector line right at the fitting on the injector that stumped me for a while. Most of the fuel hit the manifold and evaporated.

 

[WarWagon]

Found it leaking from the injector body when cold only. It was not a fun swap to get a used injector in the driver side and a good injector in the #2 hole. Lets just say 2 injectors are going in to the shop vs just one. Damn fragile return nipples..

 

[Acesneights1]

I was gonna suggest return nipple cracked. I had one do that.

 

[WarWagon]

I was gonna suggest return nipple cracked. I had one do that.

Shop says this is the exact problem. From using the wrong socket they say. 3rd engine with the same 30MM socket so why the 3rd one...

We will see if I just broke them on removal or if it had other issues when they are done repairing the injectors.

 

[Acesneights1]

Were they your injs or ones they gave you ?

 

[WarWagon]

This was a exchange reman set. They fixed the injectors, 2, and gave them back.

I am highly discouraged because the damn thing still leaks. I am under the hoods of both my rides this weekend and it hit 118 today and rained this afternoon - just enough to make it damp and hell hot.

And the injector is leaking so badly I can feel the weak cylinder, via engine vibration, at high load low RPM like climbing the steep driveway. Almost like a dead hole. Nothing like cracking a line via the injector...

 

[bk95td]

The real injector sockets do fit the injectors much better than a sloppy 30 mm socket. The hex on the injectors has rounded corners. The injector socket fits exact and has rubber insert to protect the nipples. I just bought a injector socket after using a 30mm impact socket for years.
I found my leaky line with the engine running with a bright light and watched for the light mist. All the fuel would evaporate with the engine hot. I had to check with the cold engine to see it. My leak was right at the brass ball under the line nut on the injector. Very fine crack in the line.

 

[WarWagon]

The injector shop had put new tops on the 2 injectors I had them fix. It still leaks. It is on the #3 hole now so the leak followed the injector. So I had them build me another injector. At this point I want the leak stopped - B99 ruins rubber that is leaks on like engine mounts, diff mounts, turbo drain hose coupler... I am back to #2 diesel now due to price difference.

I will see if they can fix this one again, but, I guess I don't really care. What good is 1 spare injector? I'll talk to the shop about maybe a credit.

 

[Acesneights1]

The lines can crack at the flare as well. Try swapping the leaky inj to another hole and see if the leak follows it.