LBZ fuel knock, multiple misfires?

[DIGGLER]

i just looked into this... check this out.
going by the firing order:

1 -4
2 12
7 -4
8 .3
4 -4
5 1.1
6 -4
3 6

is it odd that every other cylinder in the firing order is -4 on the balance rate value?

 

[JoshH]

From what I have read, the ones with the -4 balance rate are in the same injector group. They are grouped so the front and back cylinder on one side are grouped with the two middle cylinders on the other side. So 1,4,6,7 would be in one group and 2,3,5,8 would be in another group.

edit: I know that is true for the LB7 and LLY. I'm just not sure about the LBZ.

 

[DIGGLER]

From what I have read, the ones with the -4 balance rate are in the same injector group. They are grouped so the front and back cylinder on one side are grouped with the two middle cylinders on the other side. So 1,4,6,7 would be in one group and 2,3,5,8 would be in another group.

edit: I know that is true for the LB7 and LLY. I'm just not sure about the LBZ.

so my 1,4,6,7 group all have a -4 balance rate... is that odd, or maybe just a coincidence?

one thing i have not tried is to physically unhook each of the injectors one at a time while its running. may try that this evening if i get a chance.

 

[Yellow Jacket]

I am having this problem with a LLY, but when you unhook one injector it throws a code and shuts off all 4 injectors in that group, either 1,4,6 & 7 or 2,3,5 & 8... So it still doesn't help.

 

[DIGGLER]

managed to turn off each injector one at a time this evening as i sat in the truck tinkering with efi live. it was pouring rain. the engine would change pitch when you turned half of them off, but it was still knocking. i think half the cylinders may be fuel knocking?
i really feel like the -4 balance on 1467 is a big clue to something, but i do not know what...

 

[Yellow Jacket]

The LLY i worked on, when I turned off #6 with EFILive DVT's it would quit smoking and knocking.

I raplaced injector #6 and still the same, I read some prior testimonials after that... I borrowed a Tech 2 and when I shut off injector #4 it stopped knocking and smoking, so I replaced injector #4 and all is better.

All of the balance rates were out of spec while this was going on, but #4 cylinder was the only one that always stayed a -#, mainly stayed at -7 or around there... So I thought it might be the one once I replaced #6 and it didn't fix it...

Others thought with the DVT that #6 would be #6 in the firing order, but that doesn't work out either... #4 cylinder is 5th in the firing order...

Anyone else have any speculations or proof of which # in DVT is which cylinder for the others???

 

[Chevy1925]

The LLY i worked on, when I turned off #6 with EFILive DVT's it would quit smoking and knocking.

I raplaced injector #6 and still the same, I read some prior testimonials after that... I borrowed a Tech 2 and when I shut off injector #4 it stopped knocking and smoking, so I replaced injector #4 and all is better.

All of the balance rates were out of spec while this was going on, but #4 cylinder was the only one that always stayed a -#, mainly stayed at -7 or around there... So I thought it might be the one once I replaced #6 and it didn't fix it...

Others thought with the DVT that #6 would be #6 in the firing order, but that doesn't work out either... #4 cylinder is 5th in the firing order...

Anyone else have any speculations or proof of which # in DVT is which cylinder for the others???

Ben (duratothemax) has a big thread on that issue.

 

[DIGGLER]

Broke crank.