To make a long story short. I had an 05 and wrecked it. I replaced it with an 04.5 LLY. It was missing when you would let it go through the gears but not really accellertating hard. It would knock and roll the blue smoke.
Anyway I took it in and the said it needed #8 injector.
I brought it home and it ran good for about a week. Now when you lug it you here a lot of injector knock and it starts smoking. Ok I put Edge on it just to test some things. With the Edge on zero it really knocks and smokes. The higher the setting the smoother it runs. The dealer says they are good.
I tested the injector balance rates. My question is what should they be.

#1 0.27
#2 -1.18
#3 0.37
#4 -2.14
#5 -2.79
#6 -3.70
#7 -1.60
#8 -7.51

When it idling they will change a little bit but the stay about the same gap between them.
What is going on?:help:

+/- 4 in park @ idle or +/- 6 in drive @ idle. Anything out of that range needs to be replaced. Before any injector is replaced though the fuel pressure regulator should be graphed and compression test needs to be done. It sounds to me like there is more then an injector problem.

yes check the fuel pressure regulater.

and the wiring harnesses....

actual "injector failures" on LLY's are quite rare. Many are misdiagnosed wiring problems. Then when the technitian replaces the injectors, he unknowingly "knocks" or bumps the wiring etc and puts the new injector in and it works fine, so he thinks he fixed it.....................then the truck comes in 2000 miles later with the same problem :)

I am having the same #8 injector issue and I want to know which injector is #8? Balance rates look almost the same and it goes in on Monday. No smoke though.

I am having the same #8 injector issue and I want to know which injector is #8? Balance rates look almost the same and it goes in on Monday. No smoke though.

driver side closest to firewall.

Thanks man...I have been wanting to check the wiring on that one!

Thanks man...I have been wanting to check the wiring on that one!

no prob, have fun getting to it.

Thanks for the info. I took the wires out of the split loom from the Edu just to check for pinch points. Some rubbing but not through the insulation. I will insist the dealer go farther. I hate the fact that I bought this used and don't know the history of it. I will keep lookin and any other info is welcome.

Thanks for the info. I took the wires out of the split loom from the Edu just to check for pinch points. Some rubbing but not through the insulation. I will insist the dealer go farther. I hate the fact that I bought this used and don't know the history of it. I will keep lookin and any other info is welcome.

Go here.... http://dieselplace.com/forum/forumdisplay.php?f=72

and post the vin number for a check... That will tell you if GM has done any work on it under warranty...

That is one of the nice features of the DP.. Lots of people willing to help you :)

driver side closest to firewall.

Opposite of a gas engine?:cool2:

I had the same #8 problem at 7500 miles. At idle in drive, the truck chugged while holding the brake. At the same time, black smoke was present. I brought it in to the dealer and the diesel mechanic reset the computer. He ordered an injector but never changed it out because the problem never came back. No problems since and this was two years ago (04.5 LLY).

I have an 04.5 LLY too and I had an injector go out a few weeks ago. I have 88000 miles on it and the dealer ended up replacing all of the injectors and it runs fine now BUT, it gets terrible mileage now. I was getting 17-19 I now get 13-15. I have taken it back to the dealer for this and he says everything is within spec.

Ben

#8 is what went bad on my truck and burnt the piston. The only problem I had was hard starting in the morning,like it was hydro-locked or something. It would run rough and smoke white for a few minutes then clear up and run fine. We still don't know the exact problem,but I suspect the injector itself was leaking. Balance rates were way off at idle,around 7-8 on #8. I'll know more when the new motor goes in.

the LLy have a harness rub through problem right off the ficm (fuel module) pass side valve cover the harness rubs on the bracket that it sits on causing many weird problems