I have a similar problem--replaced the fuel lines but still have a small amount of leakage around the injectors. Someone here on this forum advised me that my problem is probably from the prechamber collars pictured here:

I was told that I may be able to torque them tighter with the injectors, but that I would likely have to remove the injectors, grind a homemade tool from a socket that fits the grooves, and tighten them that way. I haven't attempted to do this yet, but I just wanted to let you know. If you search "prechamber" in the "parts" section, You'll see prechamber collars and rings (I'm not sure if the rings are potential culprits or not). Also, there are injector heat shields that I suspect may contribute to leakage problems.