1.6 TD Head Injector Seat Issue

[beichMTDI]

Hi guys, need some help with a 1985 Jetta MF 1.6 Turbo Diesel engine that we're trying to get going. The engine has been recently rebuilt (all stock). The head had a mild 130,000 mile rebuild done by a shop. The issue we are having is its only running on 3 cylinders. We narrowed it down to the number 1 cylinder not running (closest to the serpentine belt). After confirming that fuel is getting to the injector we took it out to inspect the heat shield (injector washer). This is when we noticed an inclusion on the head seat below the washer. Here's a picture of it:

https://photos.app.goo.gl/sbOKkl8OKRcntD612

As a reference we took another injector out and verified that the seat should look like this picture:

https://photos.app.goo.gl/7iIF1BJnDt4UAP8k2

Could this inclusion be causing a pressure leak and preventing #1 from firing? Has anyone come across this before or have any insight?
Thanks for viewing!

[libbydiesel]

If that was leaking out the compression enough to cause a no-fire situation, then there would be a gale of wind blowing out around the injector.  Was there?

Have you done a compression check?

Swap one of the other injectors to that hole and see if the problem moves.  After that do a compression check.  After that either pull the head or run a small borescope in there and see what's up with the prechamber.

[beichMTDI]

Thanks for the ideas Andrew! Definitely no gale force winds blowing out of there haha. I like your idea of swapping the injectors. I think that'll be what we try and do next. I'll let ya know if that changes up the bad cylinder... If so, then we have an injector issue!
Again, thanks for the reply!