Yet another injector question...
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...
Yet Another injector question... re-assembly
I decided to pull the injectors out before ordering the new set. Then I'm ready to immediately return for the core charge once I receive the new ones. Obviously the truck isn't going anywhere while I wait, but that's OK.
So, I started pulling injectors... I used the round end of an air chisel to fit in the hole of the hold down bracket and moved the injector side-to-side and gently pried under the bracket to lift. Well, the first three injectors came right out.. along with the cups! I set them on the bench and needed two flat blade screwdrivers to pry the cup off the injector. I found the o-rings on the injectors had rolled out of the grooves and the entire body of the injector and inside the cup was caked with carbon. It seems all that crud cemented the cup to the injector, which seems to explain why the assembly came out rather than just the injector.
I thought as part of the install, that red loctite was supposed to be coated around the bottom of the cup where it seats in the head, but the cups were absolutely clean on the outside when I pulled them out. I was surprised, because the last injector replacement was done by GM under the original warranty. Am I right about using the loctite on the bottom of the cup?
I need some advice on the best way to re-install the cups and injectors. Right now I'm thinking that I need to install the injectors into the cups (on the bench), then coat the cup with loctite at the bottom and re-install the assembly into the head, using the hold-down bracket to seat the assembly. If I torque the injector into place that should hold the cup properly while the loctite dries.
Sound right or is there abetter way? Thanks again for all the good advice!
Follow-up after injector installation
I finished the new SAC00 injector installation (after all the above discussion several months ago) and now have 4000 miles on the new injectors. Initially, all of the balance rates were -0.5 to +0.5, with one exception, Cyl #6, which came in at +3.7. Still, no reason to worry. Now, after 4k miles, I noticed a little extra diesel clatter around 1500 rpm, so decided to recheck balance rates. All were within the -4 to +4 mm3 guideline, except for Cyl #6, which is now at +14. I contacted the vendor of the injectors and they agreed to replace the one injector.
I have heard horror stories about injectors that are stuck open burning holes in pistons or trashing exhaust valves. Without pulling the head can I assess if there's been any damage?