I have a 2002 LB7, with 143,000 miles. I replaced the injectors the first time at 80,000 (Warranty replacement) and am assuming GM used rebuilt injectors. Now after another 50k I'm getting black smoke at the tailpipe at idle. No increase in oil level, or fuel smell in oil.



It's important to note that I have a Kennedy MegaFilter and have been using a mix of FPPF and Cetane booster since the truck was new. I'm puzzled WHY I need injectors again, as I thought particulates in the fuel was the culprit...


Anyway, here are my questions:
1.) I was told I could buy some time before injector replacement by using additional additives. The recommendation was to use Hot Shot Diesel Extreme. Any better ideas, or do additives at this point do nothing?


2.) I'd like to do the injector replacement myself, but need info on special tools for injector and cup removal and whether it's necessary to remove injector cups, or not...



3.) I figured I'd buy injectors from Kennedy Diesel, but are the tools available there as well as all the extra parts (lines, o-rings, gaskets, etc?)



Appreciate any help you can provide...