I wished I knew what it was. I'm a stickler for details, no bore scope but used a cell phone picture to see, worked great. Actually used the #8 bore for the thread. Threads were dry, verified dry. But will tell you, cleaning that bore was not easy after it popped. Full of carbon!

Is there a direction for the copper?

 

And I'm the only one to blame... Cost me 2 bills and 2 hours!

 

It's not mentioned in the manual but newly rebuilt ones from Ford come with the ring facing away from the injector body towards the injector cup. In other words, once installed on the injector tip using a deep 9mm socket you'll be able to see this.

 

Appreciate the posts here and in addition to a handy thread from Randy this summer, I think we all know what I will be doing in the next week or two.
Hate it for the kids sake, I might just spring for the parts this time. Might be a good time to freshen up the turbo while I have some other stuff off anyway.

 

Worn rings or stuck rings will cause blow by and blow by will put fuel in oil. Pull the oil fill cap and watch the venting....if you see what looks like a steady trail of steam ...you could led have some blow by.

thin oil can increase blow by and thicker oil can help decrease it.

 

Thankfully there is very little blow by with this engine, almost hard to see it.
It did some fifth wheel duty at some point in it's former life so it was worked.