This will be a repeat of some stuff.

Sometimes people install the Injector Heat Shields upside down or do not replace them. If you drop them into the Hole the Heat Shields flip over one or more times.

Sometimes when the Injectors are removed the Prechamber Lock Ring/Retaining Collar loosens.
If that happens you are going to need a Special Tool to tighten the Lock Ring/Retaining Collar because the Torque on the Rings is fairly high.

The same theory applies to your Engine and the Newer ones with the exception that the Aluminum Headed Engine can sometimes develop a Prechamber leak even if the Lock Ring/Retaining Collar is not loose.

Also I took one of the Retaining Ring/Collar tools to the Junk Yard with me for testing and found quite a few Retining Rings were not nearly as tight as others. I do not know if they just loosen over time or it is from previous Injector removals.

__________________
84 300D, 82 Volvo 244Gl Diesel