Diesel injector not pumping

[Hermit Scott]

I recently rebuilt a YSM 12. I put it in the boat and it ran while I sprayed WD40 in the intake. I traced the problem to the injector. IT IS NOT PUMPING. I took it out and went through it so many times I don't even have to look at the book to put it back together!
I took it to a shop in San Antonio and they couldn't test it, didn't have the right adapter plate. I have submersed this pump in diesel and bled it and pumped the plunger over and over. It will not push fuel through the high pressure side. Everything looks to be in good shape.
My question is this, to any one with knowledge of this type injector, IF I do not replace the internal copper washers after I have disassembled the pump and reassembled it, will the pump not seal on the inside? And how can I tell where the things is leaking from?

 

[ITMaster]

I never rebuilt mine

The last time that I did any extensive work on an engine with a fuel injection system, they were cheap enough that I just replaced them, I am thinking they were only $27 each, so to me it was just as easy to replace them instead of trying to tear them down and rebuild them and reassemble only to have a small piece of junk clog the injector up and mess up the atomizing of the fuel. Course, it was a little over 10 to 12 years ago, I haven't a clue what the cost of replacement injectors would be now days. Hope they are still affordable when I need to worry about it. Perhaps I should get some BG or Techtronic and run it through a tank full of fuel pretty soon.

 

[Hermit Scott]

injector

They cost $290. But about 140 to rebuild.