ive got an 04.5 116000 miles staight piped air box mod egr blocked and diablo predetor or 85. my truck has been runnin kinda rough off and on while in drive and on the brakes puffin white smoke. now white smoke from a diesel how i kno it is over fueled?? well i just checked my balance rates with the predetor they all seemed to jump around quite a bit with 2-7 from 5 to 0 but 1 was way high like jumping from 14to 9 or so. im not exactly sure wat the ballance rates mean but my interperation it that this is the rate the fuel is flowing through the injectors?? please correct me if im wrong and edjimicate me. also wat do u all think could be causeing my problem thanks in advance

Balance rates should be at or below 4 when in park. (-4 to +4)
The one that you have at 9-14 is most likely a negative number...........meaning the computer is trying to compensate by pulling fuel out for an injector that is 'dumping' too much fuel. This is a common symtom.
FYI..........be carefull swapping only one injector..............it is common to find another 1 or 2 bad after doing the initial swap!
Good luck, Ed.
On edit.........you should/could be in warranty! Hopefully, GM will do all 8!

thanks ide have to look again but im pretty sure it wasnt a - number cuz thats wat i though was funny was it being high. maybe ill give the dealer a call and ask them about warentying it but im guessing that i would rly have to fight with them to get them to do that.

Hopefully, someone else will chime-in here...........I don't remember the details of the extended coverage on injectors for the LLY.

There is NO additional coverage for a LLY engine after- 100k miles or 5 years! Anything done after that is at the approval of GM and is considered a "Goodwill".

I've found that my balance rates are wierd when running a tune. I always check mine on the stock tune. They seem more stable then.

There is NO additional coverage for a LLY engine after- 100k miles or 5 years! Anything done after that is at the approval of GM and is considered a "Goodwill".

Thanks.:D I can barely spell 'LLY'............I'm an LB7-kinda-guy!;)
So, anyway........the O.P. is back to saving his injectors or replacing at his cost. Not the best news.............Good luck.
Ed.

in park balance rates should be -6mm to +6mm. then run put it in N and do it again. tests should read out to -4mm to +4mm. BUT a handheld tuner does not give accurate data when it comes to a balance rate. the only true 100% way to know what the injectors are doing is to get a Tech 2 hooked up. the specs that i listed are what the tech 2 should read if the injectors are good.

thanx for the info could my buddies snapon scanner give me more accurate balance rates?

The spec in P or N is +/- 4.0

In gear its +/- 6.0

No particular device is going to be more 'accurate' then another, they are all reading the same data stream.

Balance rates are an indication of overall cylinder condition. They take into account any compensation for compression loss, leaking injector tip, even a bad fly wheel for you handshaker guys.

Injector 'on time' as measured in mS must also be considered. If you look at them with a scanner, you will find them to likely be in the .40-.60 mS range. If you see a group of them hovering around a constant range, but one seems to fall short, maybe around .20mS or even 0, then that will give you a more accurate indication of how the injectors are working.

Edit: This info is only accurate at an idle when the ECM is balancing. Once your off idle or above, the ECM is no longer trying to 'balance' and the mS will be the same across the board, even with a bad injector

Short and sweet version: Everytime the engine fires, it speeds up the crankshaft. Not anything you will notice, but the ECM is fast enough to see it. If a particular cylinder fires and the ECM does not see the speed up its anticipating, it will add a bit more fuel the next time around. If its seeing too much of a speed increase, it will back the fuel off on that particular cylinder. Now, if you have a injector tip that is leaking, its putting fuel in the cylinder all the time. Thats why you see smoke from the tailpipe, the injector never seals, its dripping fuel in and its not atomized, that along with the engine being on the wrong stroke it just pushes it out the tailpipe as white or grey smoke. Since the injector is always putting fuel in the cylinder, the ECM see's that when it speeds up when that cylinder fires. It keeps pulling fuel out until it will get to 0.

Eric would certainly be better poised to weigh in on my solution... but a bottle of Power Service Diesel Kleen has been known to settle down many a set of irritated injectors. It's a cheap fix, and if it doesn't solve the problem, you're out maybe $7.