Another smoking LB7

[wirewrangler]

Well, sigh,

As stated in the introduction thread I posted, I'm assuming I'm going to need to replace the injectors in my LB7. I gather that looking at balance rates aren't the whole picture but the grey smoke that I see everytime I fire it up is the best indicator. Attached is a screenshot of the balance rates - how long can I drive it like this without screwing something up?

The current injectors are the first replacement set that went in around 50k miles ago and I bought those from LDS; I'm pretty sure they are bosch remans; whatever $1800 bought in March of 2013.

It sounds like the 45% SAC style nozzles are the way to go reading some other threads. If I go that route, will my J/K 100HP tune run those or do I need to budget in some tuning to go along with these?

Thank you for the advice,

Wes

PS - Looking for a Federal Y bridge; stock or aftermarket (mild)

 

[2004LB7]

Your balance rates don't look that bad. Number #1 is close but still under the limit. To be sure we need your main mm3

How's your fuel pressure? Have you checked compression? How about injector cleaner?

 

[TheBac]

If you do end up going with sac's, Id ask John if he can retune for them if need be.

 

[wirewrangler]

I’ll run another data log with mm3 included. I spent some time trying to figure out how to get the data from the v2 to the laptop and haven’t figured it out yet; any tutorials you recommend?

Wes


Sent from my iPhone using Tapatalk

 

[2004LB7]

Try here:

https://support.efilive.com/kb_article.php?ref=9562-EUAF-6679

 

[Brent@LDS]

Your looking at the common VCO nozzle issues. I would recommend having them sent in tested and taken to the SAC 45 which is very common for us to do here.

 

[wirewrangler]

2004LB7,
I did a round of data collection with different PID's still including balance rates and the mainrate that you suggested. I don't have a fuel pressure gauge so I'm not sure what the pressure is except for the data point that I logged. I haven't ran a compression check on it. I've run stanadyne over the years; usually always has some in the tank but I haven't done any type of deep cleaning method if one exists. BTW, the link you had me try was informative and helped me out alot; thank you.

Brent@LDS,
If I'm understanding you, I send my injectors to you, you test them, make sure they're good, if they are good - replace the VCO nozzles with the SACs and send them back?
What happens if some are good and some are bad?
How long does this take on average?

Thanks guys,

Wes

View attachment E54_0003.zip

 

[Brent@LDS]

2004LB7,
I did a round of data collection with different PID's still including balance rates and the mainrate that you suggested. I don't have a fuel pressure gauge so I'm not sure what the pressure is except for the data point that I logged. I haven't ran a compression check on it. I've run stanadyne over the years; usually always has some in the tank but I haven't done any type of deep cleaning method if one exists. BTW, the link you had me try was informative and helped me out alot; thank you.

Brent@LDS,
If I'm understanding you, I send my injectors to you, you test them, make sure they're good, if they are good - replace the VCO nozzles with the SACs and send them back?
What happens if some are good and some are bad?
How long does this take on average?

Thanks guys,

Wes

View attachment 48008

View attachment 48009

View attachment 48010

View attachment 48011

That is correct, we would baseline test them. If they test out good put a set of SAC 45 nozzles on them and retest/balance them. If there are any that test bad they will have to be replaced with a new unit.

 

[wirewrangler]

Brent,

Alright, I've got a few more ducks to get in a row, I'll be contacting you.

Thanks,

Wes

 

[Brent@LDS]

Sounds good! We will get you taken care of!

 

[wirewrangler]

I went to the chevy dealer and bought some x66p upper engine cleaner and did a round of that on thursday night. Didn't smoke while burning that stuff mixed with diesel and the balance rates did improve some. I hooked up the fuel lines and it immediately started smoking again. I was hoping to buy a little time...

I did notice that when I switch from the 100HP tune to the 40HP tune, the balance rates change and get tighter. When I switch to the 100HP tune, there is an audible difference but I'm not sure where it's coming from; I'm not going to worry about it just thought it was interesting.

Have any opinions on injector pulling tools - looking at this one https://www.cpooutlets.com/sp-tools-11700-duramax-lb7-injector-puller/slyn11700,default,pd.html

Any other data collection or testing suggested before I rip into this? I'd like to do this once...

Thanks,

Wes

 

[Burn Down]

I just use a small snap on heel bar to pull lb7 injectors... I also always pull the cups too, to far to go back in if one leaks imop.

Also if your going to use a non stock tune for balance rates you need to know what they read when you put the injectors in and what they changed to after the tune, you need a base line. If unknown then put the stock tune in to ck balance rates.

 

[wirewrangler]

I'll put the stock computer back in and check the balance rates again. I'll probably run a compression check as well. Regardless, unless I stumble onto something else causing smoke, they're coming out along with the cups/sleeves.

Thanks for the input.

Wes