LB7 / LLY Injector assignment dispute

[GMPX]

Hi All,

For quite some time now we've had people saying the DVT controls for injector shut off's are assigned to the wrong injectors. I've had yet another look at this today, I've come up with an alternative, but somehow we need someone to be able to confirm my table is the correct assignment.
On the left is what we currently have, on the right is what cylinder number 'might' be the correct assignment.

If anyone can somehow confirm this on a truck it would be greatly appreciated.

DVT Name
Injector #4 = #5
Injector #8 = #8
Injector #3 = #1
Injector #6 = #3
Injector #5 = #6
Injector #1 = #2
Injector #7 = #8
Injector #2 = #7

Cheers,
Ross

[rcr1978]

Ross, is this what you came up for the LLY? I just checked my LB7 this week and found that the DVT numbers are correct to witch cylinder is actualy turned off.

[GMPX]

Ross, is this what you came up for the LLY? I just checked my LB7 this week and found that the DVT numbers are correct to witch cylinder is actualy turned off.
Well, I don't know then, why are people contacting us saying it's wrong? On all Duramax's I believe.

[rcr1978]

The only one that I have heard that was a problem was LLY, but I don't think anyone has actualy confirmed right or wrong with actual testing other than just swapping parts. I tested the LB7 with a scope. Maybe the problem is the balance rates possibly being reported wrong for what cylinder is witch and not the actual DVT tab?

[GMPX]

Well, I clearly remember people saying they swapped out good injectors because the injector number they shut down on the DVT's turned out not to be the bad one. I suppose we'll just let this thread run it's course and see what pops up.

[THEFERMANATOR]

Well, I clearly remember people saying they swapped out good injectors because the injector number they shut down on the DVT's turned out not to be the bad one. I suppose we'll just let this thread run it's course and see what pops up.

It was Ben with his LLY that said he had problems with the wrong injector being shut-off. I can try and go down this week and check my balance rates on my LB7 with EFILIVE and then recheck it with a TECH2 and see if they coincide.

[wilsonck]

I have a lly and balance rates work fine.

[THEFERMANATOR]

I have a lly and balance rates work fine.

They work, but it is in question as to wether or not the injector assignment is correct and if the EFILIVE data is reading teh correct cylinder for the balance rate.

[wilsonck]

I don't want to argue, but I used the balance rates to change an injector that had bad rates. I had high rates + 7 or 8 on injector 7, changed it out and it was good after that and still is. So it worked fine for me.

I had tried using the DVT's as well to determine which injector was bad, but that didn't work for me. This is what others found too if I am not mistaken

[GMPX]

I had tried using the DVT's as well to determine which injector was bad, but that didn't work for me. This is what others found too if I am not mistaken
Correct, the balance rate display is not in question, never was as far as I know, it's the DVT injector assignment to shut them off that is the possible issue.

[wilsonck]

yes, that is what I encountered and others encountered from my readings.

[THEFERMANATOR]

I went back and reread Ben's post and seen where he said he couldn't get a good read on balance rates so he went to shutting them. I thought he had posted about a high balance rate on that one and that was why he was hutting it off. My bad, I misunderstood his post on it.

[Pusher]

The 3 injectors I have changed after checking them by shutting them off 1 by 1 have all been correct. All were on LB7's.

[LB72004]

is it possible that the confusion is in the firing sequence vs cylinder number? efilive is displaying one while the tech2 is displaying the other

[GMPX]

The 3 injectors I have changed after checking them by shutting them off 1 by 1 have all been correct. All were on LB7's.
That is good to know. I think we might just leave them as is.

[JustinD]

I used the DVT controls to pinpoint which injector was bad by shutting them off one at a time until it stopped rattling so bad, worked for me? I do know that sometimes it reads all zeros for balnce rates even idling??? But the Tech II did the same thing???? Can an injector go so bad it won't read or let any others read?

[THEFERMANATOR]

I still can't believe that nobody with an LLY has chimed in yet? The LB7's weren't in question as far as I knew, but LLY's were.

[mtl_dmax]

I still can't believe that nobody with an LLY has chimed in yet? The LB7's weren't in question as far as I knew, but LLY's were.



X2


As people can see here, someone with a scope has verified that that the LB7's are in the correct order in EFI.

http://www.duramaxdiesels.com/forum/showthread.php?t=27243&page=6

At this point we need someone with a scope to verify the DVT cylinder shutoff order for an LLY since that was the one that appeared to be causing the issues Ben was seeing at the start of the thread.

[OTHRGRL]

Spent a few hours last night figuring this all out. It is more complicated than any of us even thought. It has no correlation to firing order. I'm going to discuss things with Cindy and Ross first and see if they can fix it before me wasting time posting how and what we found, only for them to fix it and make it a non-issue.

[messejme]

Thanks for the time spent to clarify this problem. Looking forward to the fix.

[rcr1978]

I would like to know what you found.

[mtl_dmax]

It's been a while since the mystery was solved, any word on if the software will be revised or someone will let us know what the real table is for an LLY?

[wilsonck]

It's been a while since the mystery was solved, any word on if the software will be revised or someone will let us know what the real table is for an LLY?

x2...

[GMPX]

I'm still not convinced an issue exists. The LB7 guys are saying it works perfect, the commands sent for cylinder disable are the same on every GM controller, so if the LLY is shutting off a different cylinder to what the LB7 does then I don't know how we can fix that. But without confirmation that is actually happening we can't progress.

[mtl_dmax]

Hi Ross, that's fine if you can't fix it in the software, but having the table to translate it properly would help tremendously. It seems clear to me and others that for some reason when you shut off cylinders on an LLY with EFI (only on the LLY's), it does not correspond to the physical cylinder yet when the same request is given by a Tech 2, the order is correct. Unfortunately I'm not a programmer so I can't speculate why this might be. While both the ECMs on the (E60) LLY and (E54) LB7 are made by Delphi and both the FICMs are Bosch, I can only surmise that there must be a difference somewhere causing this to happen. It has certainly been well documented that the LB7 and LBZ are correct in the DVT and I thought both Ben and Dustin (among others) found evidence that the LLY's aren't.

Here's another example of where it didn't correspond to the DVT in EFI (on an LLY):
http://duramaxdiesels.com/forum/showpost.php?p=443293&postcount=46


Can you at least share what was found so that we might be able to assist with a solution?

Thanks in advance for your work on this issue.

[Hustlin diesel]

I have the same question about the lb-7 I got a bad #4 injector according to efilive balance rates so I got a new injector and replaced it and the balance rates are still the same and still has a hard ( extended) start same as before I replaced the second injector from the front on the drivers side I'm wondering if it is the fourth in fireing order which would be number 8.

Would like some info on this before I tear into it again

[mtl_dmax]

I have the same question about the lb-7 I got a bad #4 injector according to efilive balance rates so I got a new injector and replaced it and the balance rates are still the same and still has a hard ( extended) start same as before I replaced the second injector from the front on the drivers side I'm wondering if it is the fourth in fireing order which would be number 8.

Would like some info on this before I tear into it again

The LB7 order should be correct in EFI so if you still have bad balance rates it must be another reason. It certainly sounds like you also located the proper injector too. You didn't mention if the balance rate was positive or negative but if it's positive, then I would do a compression check and see if you have any mechanical issues causing your poor balance rate. Also if you are having trouble starting the truck you need to verify that you are building at least 1450 psi (preferably alot more) while cranking. If you're not building pressure then you need to figure out why.

[Hustlin diesel]

It's taking a long time before it hits 1400 psi as soon as it reaches 1400 it fires right up. Balance rate is +5.33 ish while all the others are within +- 1.5

[Hustlin diesel]

There is also some white smoke and it has more injector rattle when your driving so it must be an injector causing this

[THEFERMANATOR]

Do a return rate test, balance rates is but a SMALL part of the story, and shouldn't be used definatively to find a bad injector.

[Hustlin diesel]

Not very easy doing a return rate test on the lb7's tho unless you do 4 at a time

[THEFERMANATOR]

Not very easy doing a return rate test on the lb7's tho unless you do 4 at a time

You pretty much need the KENT MOORE kit to do it. I know my local dealer lets me use theres as I buy my injectors from them in return.

[Hfg Trucking]

Hey guy i am new to the forum and was looking to get a efi live for my lb7s and one of my friends told me i should talk to THEFERMANATOR to get a efi live. i am sorry if i am posting in the wrong place i will learn how to use this forum soon..
If you can let me know on how to get one let me know.
Thanks

[mtl_dmax]

You pretty much need the KENT MOORE kit to do it. I know my local dealer lets me use theres as I buy my injectors from them in return.

Seems like you could rig something up to test the injector banks but I have no idea how you would test individual injectors on the LB7 since the return lines are under the valve cover. Sounds like you'd need some 100ml graduated cylinders and then get creative on how to attach the return lines (doesn't need to be pretty). I know I've done it on LLY+ trucks without the KM tool ($$$) but I would think you could at least get a return per bank on the LB7 (even a total injector return would be ok to indicate an issue......8 injectors returning less than 40 ml for 15 secs cranking). Maybe I'm missing something though.

Here's the procedure for it:
http://www.duramaxforum.com/forum/1270490-post10.html

You should be able to isolate the return from the injection pump too:
http://www.merchant-automotive.com/images/products/detail/20100609_00001.jpg

The OP may also want to replace one of the rubber lines after the filter head with a temp clear vinyl hose to make sure you have good fuel supply (ie no air bubbles and hose doesn't collapse).