The Dirty LB7 strikes again
 

Hey guys, I have an 01 Sierra with an LB7. Just did head studs, injectors, heads rebuilt, airdog 165. I rebuilt the motor and it ran perfect for about a week and now I have a bad knock and crazy balance rates. I understand that it could be a stuck injector but I'm not having any luck figuring out which one or if it is an injector at all! I have to get this thing figured out. It starts and idles fine other than the knock. With the injectors unplugged and turning the motor over everthing sounds nice and quiet. Check out these balance rates. I don't get it. I know you guys can help. AAAAAHHHHHHHH!

Anyone know if injector 4 is cylinder 4 or 4th in the firing order which is cylinder 8?

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Wow nothing? Come on, I know somebody has some idea.

i only know that with EFI Live & Tech 2 on the LB7s when shutting off #4 it is by cylinder. i would think that #4 is referring to cylinder numbers and not firing order

i am not familiar with the Edge so i dont know if they did something different

I always had more luck posting these types of questions over in the specific section for the engine, for you the LB7 section. I know this place is designated for these problems, but try posting over there too.

Thanks for the help. I'll try that. I did call Edge yesterday and they said that the injector number on the cts is corresponding with the cylinder number. It was just confusing because I've heard of EFI Live being different.

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I swapped out cylinder #4 injector and it made no difference. I hate changing parts and just guessing.

the issue seams to be with the LLYs

LB7 / LLY Injector assignment dispute