Questions that have come up while working with injectors

[gcoffelt]

Hello again all,

I have been (very slowly) working on replacing the injector nozzles, and many other complications have come up while going along.

The main one is that I have had a very difficult time getting the old heat shield crush washers out: The previous owner believes the injectors have not even been touched in it's 200,000+ mile life. I've managed to get 4 of the 5 out, but that one is simply refusing. Anybody have strategies for this? I had a little pick tool that broke at the handle while trying to take this last heat shield out.

This part is more me venting than asking a question: Another difficulty is that one injector is I believe not tightened together all the way and/or assembled wrong internally. I got everything back together (after hours and hours of trying to remove the one pesky heat shield and saying screw it), bled out the air properly, and just before it sounds the engine is going to turn over a whisps of fuel come out of that one injector. Note this injector is not the same one with the old heat shield still in it.

Thanks again everyone,
Geoff

[Diesel911]

Here is a thread with a similar stuck heat shield problem:
Removing Injector Crush washers

Look in section 07 diesel injection there is 2 sub-sections on injectors.
http://www.pauldrayton.com/uploadfiles/merc/Service/W123/Index/617Tindex.html
You did not say exactly where the fuel was spraying from.
However, there are a few possibilites. Dirt or some other foregin material could have gotton between the precision surfaces inside the injector an are keeping them from sealing. The precisions surfaces inside the injector may need to be lapped (they do this when they rebuild the injectors) flat and are not sealing. Parts inside the injector not assembled properly. All of these could cause a leak between the injector nut and the upper injector body.
If the Fuel Injection line is not seated well into the top of the injector due to wear, damage or dirt getting traped under it when you tighten down the Injector Line Nut it will leak there. Cross threading of the Injector Line nut will also cause a leak in that area of the injector as it will also not seat well.
You could have developed a tiny hole/crack in one of your Fuel Injection Lines.
Keep your fingers and other body parts away from any high pressure fuel comming out as it will easily inject into your skin.
If It was me I would remove the injector, take it apart, inspect the parts (I would lap the precision surfaces), re-assemble the injector making sure the parts are assembled correctly and try it again.
Another option is to have the injector pop tested at a shop or if you have a pop tester by yourself.