Kent, I am having trouble with one of my five injectors nailing. Could you lend some advice?
History:
I sold my 82 and bought an 85 with less miles. I noticed that it was running a little rough and was smoking pretty bad. I figured that this would probably be cured easily so I brought it in and did some services on it including valve adjustment, diesel purge, cleaned the ALDA lines, and ran some 85 plus in the fuel. It continued to smoke (though not as bad) so I thought next that it was probably the injector tips so I bought the injector tips from you and followed your instructions on how to replace them and clean the injectors. I reinstalled them and no dice, still smoking and it was then that I noticed the nailing (I cannot remember if it was doing this before. It’s possible).
Troubleshooting:
I first set out to identify where it was coming from. While the engine was running, I loosened the fuel line on the top of the injector for each injector, taking time to listen and see if the noise went away. I was able finally to determine that when I loosened the nut on the injector feeding cylinder 5, the metallic noise would completely go away (although the engine would struggle). At this point, I wanted to make sure that it was the injector causing the noise and not something specific to the cylinder (piston rings, bearings, whatever) so I swapped injectors 4 and 5 to see if the noise followed. It did.
Now, having narrowed this down to a problem with a specific injector, I figured that I should probably go get it tested at the local shop, so I pulled all of them and headed down. To my surprise, all of the injectors were popping at exactly 1800 PSI. The only thing that the mechanic noticed was that the injector nozzle on the problematic injector was not seating well on the heat shield. He was able to identify this because 4 injectors had a shiny ring on the injector nozzle where they fitted against the heat shield and the problematic one did not. I replaced the heat shields, so no, I am not reusing the heat shields.
I took these back home and reinstalled all of them and torque all of them down to spec except for the problematic injector which I torque to spec +5 for good measure. I fired it up expecting to hear a really smooth diesel and again, no dice. Still nailing. I then took the problematic injector out to have a look inside and see if I maybe put a piece in backwards, but everything was good with the exception of a lot of carbon built up from it not seating well. There was a light ring on the nozzle this time, but not as prominent as the others were. I thought that this may be due to it having carbon build up from before when it wasn’t seating well at all.
So, that’s where I am. My thoughts are that I will need to either replace the injector entirely, which would be a shame given that it is popping at spec. Any advice here? Can I reface the lower part of the injector so that it seats better? Where can I buy an entire injector?