Was working on getting the blower to go faster than minimum speed today and had a look over the rest of the engine compartment. I noticed a bit of black stuff that looked like it was coming out of the prechamber collar ring. It was very hard and brittle; looked like melted plastic. It also looked like somebody oversprayed some black spray paint onto the underside of the intake above the injector. I chipped off the black stuff for further inspection and couldn't figure out what it was.
Drove the car around town a bit after and noticed a new sound. Took a look and found compression making its way out in the same area. I have a bunch of spare injector heat shields laying around so I decided to pull the injector and check what's going on in there. The seat and threads were a bit dirty so I cleaned it with a little diesel and a chunk of shop towel. Proper torque applied and got everything hooked back up. Leak unchanged.
Here's a youtube video where you can hear the leak around #2. In the last part I squirt some degreaser on the injector and you can clearly see compression making its way out. The cylinder still fires OK. Hope the prechamber seats aren't shot...