Take a look, need some guidance

[holsky]

Hey guys,

I just did the passenger side bank injectors on gf dads 03 with 110,000 miles. Was getting two injectors with a pretty high balance rate so that's why we decided to go with that side to swap out.

Balance rates before:

Here are the injectors 1,3,5,7.

From how much gunk is in #1 and the rate was good I can't believe how little of stuff was in 7 and the rate be so far off.

Here is a picture of the rates right now with the 4 reman injectors.

The truck is still hazing but not as bad as it was. Seeing what I'm seeing and tell me if I'm wrong but if there is that much junk in and injector and it's not getting the proper fuel/pressure the ECM is going to tell another injector to inject more fuel to compensate for the bad one . But what I'm trying to figure out what exactly does the balance rates mean.?

But after all of this I guess I should have replaced all 8 instead if just the four.? And why is #7 still so high after I replaced it?

Thanks
Austin

 

[IdahoRob]

Austin, the gunk in the supply side of the injector most likely came from the fuel line when disassembling. Very common, always best to either clean the fuel lines very well or replace them doing an injector job. If the lines were not perfect, then this may be causing a problem again. The balance rates measure crank rotation of the cylinders, the ecm will adjust fuel rate to make up for weak or too powerful cylinders. Basically trying to balance the engine for smooth idle. GM spec is +/- 4 in neutral and +/- 6 in drive.

 

[holsky]

Austin, the gunk in the supply side of the injector most likely came from the fuel line when disassembling. Very common, always best to either clean the fuel lines very well or replace them doing an injector job. If the lines were not perfect, then this may be causing a problem again. The balance rates measure crank rotation of the cylinders, the ecm will adjust fuel rate to make up for weak or too powerful cylinders. Basically trying to balance the engine for smooth idle. GM spec is +/- 4 in neutral and +/- 6 in drive.

Ok thanks Rob. I did clean the injection lines before I put them back on and made sure there wasn't any rust or anything.

I guess I'm just trying to figure out about the haze it has now if I really need to replaced the other ones. It did get a lot better but it's still there just at certain times and it doesn't smell like raw fuel as bad as it did.

 

[Joesixpack]

You might try elevating the rail pressure and then do single cylinder cutouts. If the leakage is bad enough it the offending cylinder will have more knock from the early fuel.

 

[holsky]

You might try elevating the rail pressure and then do single cylinder cutouts. If the leakage is bad enough it the offending cylinder will have more knock from the early fuel.

How high should I go on the rail pressure without messing anything up? And you mean by offending cylinder will be the opposite one. Say turn off #1 and #2 will have a fuel knock if its bad or what? I dont have a clue about these duramaxs. LOL

 

[DirtyMaxx03]

Unplug the FCA from the cp3. You'll see a leak if you have one.

IMO you should have replaced all the injectors. You will be anyways

 

[Joesixpack]

How high should I go on the rail pressure without messing anything up? And you mean by offending cylinder will be the opposite one. Say turn off #1 and #2 will have a fuel knock if its bad or what? I dont have a clue about these duramaxs. LOL

Offending not opposing, so if you turn off number 1 and the knocking goes away that is the bad injector. The good cylinders will be hard to notice any sound change when you turn them off. 140Mpa would likely be enough.

But that said even if you found the hazing one on the other side you change all 4, as the tear down time is stupid.

We've seen new sets have a injector go bad after a few months so then you start looking for singles.

 

[holsky]

I was really curious to see if there had been a tuner on this truck previously so I pulled the stock tune out and looked and it seems to be the same as an 01 stock file I have but I noticed just a few numbers were slightly different, maybe there is a difference between the early model lb7s then the later ones. So I went ahead and threw a 50hp tune on it for curiosity, well the next thing I knew it hazed just as bad as it did before the new 4 injectors. Now that I'm looking through my tunes the egr was disabled on the 50hp tune, would the egr with the stock file pull in that much exhaust to mask the haze?

 

[holsky]

Disregard that last post. Wasn't thinking too straight on that! Ordering 4 more injectors and going to do the other bank. I'll let y'all know how it goes.

 

[holsky]

Just wanted to let everyone know that I got the truck fired up last night after doing the drivers side bank and it seems like its good to go, its not hazing anymore!

Thanks for the help fellas!