Can timing resolve nailing issues?
 

I have been in the slow process of replacing injectors lately. I have had a nailing problem with the #6 injector. I replaced it and the nailing went away. Two weeks ago the nailing came back and the car runs rough at start up. I have used a stethascope and know the nailing is coming from the injector. I replaced it last week and it still nails. Could this have to do with the timing?

Timing wouldn't affect just one injector. Having said that if you have never checked the timing before you probably should. Have you tried swapping the suspect injector to another cylinder and seeing if the nailing follows?

How does the pre chamber look? The ball should be pretty tight and it should be clean. Are you sure it isn't a lifter acting up?

I have swapped the injector to a different cylinder and the nail goes away. I have not inspected the pre-chamber but know by cracking the injector line that it is the injector. The sound goes away when there is no fuel pressure on the injector. I had the timing checked but found the shop did not check it with the proper tools. He manually adjusted it and charged me a hundred bucks:mad:

What is the "ball" and what purpose does it serve?

Its there to atomize the fuel. The injectors squirt a tight stream. When the stream hits the ball it atomizes out in all directions promoting an even burn in the prechamber.

When you loosen the injector line fitting on #6. Is the rpm drop the same as on # 5 when you do it? Should be almost identical with a good engine and everything in time. I would check the prechamber ball and see if the chamber is pretty clean as a preliminary step as well. Wondering if you might be having a delivery valve issue but do not know enough to comment. Engine used to run much better?

How many miles on the injectors. The nozzles are probably pretty much worn out if over 100k on them.

........untrue in many cases, Russell. Mine were tested at 180K and four were perfectly good. Had to replace one.

The SD has absolutely no smoke and got 29.5 mpg on the last tank. Difficult to argue worn out nozzles.........;)

I just got a pop test machine and am going to do that this week. I have replaced 4 of the injectors as they were in rough shape by looks. I have been replacing them with rebuilt bosch injector body and nozzles.