Considering DD'ing 350k mile LB7?

[DAVe3283]

You definitely have a security issue. I'd clear the codes and try the security relearn again. With that code set, you know why it's not wanting to start. If the security relearn fails, you can start diagnosing that whole process.

Keep an eye out for codes in the BCM as well. That could be the root of the issue too.

 

[fl0w3n]

You definitely have a security issue. I'd clear the codes and try the security relearn again. With that code set, you know why it's not wanting to start. If the security relearn fails, you can start diagnosing that whole process.

Keep an eye out for codes in the BCM as well. That could be the root of the issue too.

I cleared the code, but I still need to do a relearn? I can’t pair it through a function in the Tech 2?

I played around in the BCM menu a little, didn’t find anything that stood out yet.

 

[DAVe3283]

If you have a stock tune and TIS2Win or TIS2Web, you can do an instant learn. But I've never had that work with a tuned ECU.

 

[fl0w3n]

Well I got it to pop for maybe .5 seconds while cranking

It’s telling me I’ve got
P0201 Injector 1 Control Circuit
P0203 Injector 3 control circuit
P1261 Injector Positive Voltage Control Circuit Group 1
P1262 Injector Positive Voltage Control Circuit Group 2

And then a bunch of egr and generator L and generator F codes

 

[pmason92]

Not to bombard your thread. But I'm sure everyone wants to know where you got these Bluetooth injectors.

 

[fl0w3n]

Not to bombard your thread. But I'm sure everyone wants to know where you got these Bluetooth injectors.

:roflmao:

They’re pretty fricken sweet. Anyone need some let me know.


Miraculously plugging them in and it fricken starts. Huge fuel leak out of the CP3 line to the distribution block, tightened it up and getting ready for a test drive.

 

[fl0w3n]

Starts runs and drives now. Took it around the block a couple times. I need to get the thermostats to open so it can burp coolant and I can finish filling it. A few little non-critical odds and ends need to get buttoned up, mainly unrelated to the work I just did.


This is weird though - Actual is way higher than desired, is that because I’m not tuned for the LBZ FPR? Idles smooth and doesn’t lope at all.

 

[DAVe3283]

Yes, the LBZ regulator takes more current than the LB7 regulator, especially at idle. If you have a lift pump, even more so. But that's an easy tune adjustment.

 

[fl0w3n]

Yes, the LBZ regulator takes more current than the LB7 regulator, especially at idle. If you have a lift pump, even more so. But that's an easy tune adjustment.

Is it a normally open valve? More current closes it? I do have a lift pump now, it’s an air dog and I actually forgot to see if the pressure is turned all the way down.

 

[2004LB7]

Yep. Takes current to close the valve. Unplugging it will send it to max psi.

 

[fl0w3n]

Got it. Is it weird that it’s not loping at idle and runs pretty smooth actually then?


Also, big thanks to everyone who contributed to the thread and answered all my questions. Couldn’t of done it without the community help.

 

[fl0w3n]

So I took it for a little longer drive through town to try and warm it up and get it to burp coolant, which I got it to do, but also it started to lope now as i let off the throttle and coast to idle.

Also, wouldn’t let me get up past 2k rpm. Started to break up like it was hitting fuel cut off.

Also realized my alternator isn’t charging, and for some reason the truck doesn’t like 6th gear. Couldn’t get it in at first, and once I did it spit it back out after a minute

 

[fl0w3n]

Welp... now I’ve got much bigger problems. Truck is stuck in two gears somehow. Regardless of shifter position, even in neutral you can let the clutch out and it starts to grab. Throw it in first and it won’t go anywhere.

 

[fl0w3n]

Just a small update

I still took the truck to the local shop like I had planned so they could bust their knuckles on the down pipe, up pipe, and exhaust. Wound up having them throw an alternator in too. They went to load the tunes in and said they had a problem they’d never seen before. First they tried to do it in the truck, and they said the ECM wouldn’t take the vin license. It would go through the whole process but then say something like no valid License. I guess they pulled it and tried with their bench flash machine and same result. So they’re sending it to SoCal Diesel to diagnose. All in all, that took them four fricken weeks. Annoying but oh well.

So this weekend I finally went to pick it up from shop 1 in SoCal to tow it up to NorCal and take it to shop 2 who’s going to R&R the trans.

My POS 2500 Burb surprised my and made the 700 mile round trip without a single fuss.

Now I wait and see what the trans issue is, and what SoCal says about the ECM.

 

[2004LB7]

Did you or the shop try the efi live scan tool to check / fix the vin? The scan tool seems to be the preferred method for vin alterations

 

[fl0w3n]

Did you or the shop try the efi live scan tool to check / fix the vin? The scan tool seems to be the preferred method for vin alterations

I personally don't own any EFI live tools yet


I am not sure what the shop tried, it was 5:30 PM on a Friday afternoon and I was picking the truck up the next day. They probably just fumbled with it a few times and then gave up.



Pmason92 didn't have any issues getting his EFI live to activate a vin license and get into my truck like two years ago


I'm trying to buy a spare ECM from RPM Motorsports as backup just in case.

 

[fl0w3n]

Going to derail my own thread...

I’m looking at picking up a second Duramax to leave stock and DD, coming to the realization the 350k mile ZF6 one will continue to be a project as I take it to where I want.

I was shooting for an LLY or even LBZ again but found what looks like a real clean 04 LB7 with 145k, guys owned it since 10k miles and said the dealer replaced the injectors around 100k

What I’m wondering is it a guarantee the dealership used genuine Bosch injectors or is there a chance they used some lesser injector that might wind me up in the same spot in 5k miles?

 

[2004LB7]

The dealership near me only uses genuine bosch injectors. It's likely yours did too

 

[TheBac]

If they wouldve failed, they wouldve failed already. Every LB7 is an eventual injector job. Big deal. SAC00s and be done with it.

 

[fl0w3n]

The dealership near me only uses genuine bosch injectors. It's likely yours did too

That's what I'm figuring. He's going to get the invoice from the dealer and hopefully that tells for sure.

If they wouldve failed, they wouldve failed already. Every LB7 is an eventual injector job. Big deal. SAC00s and be done with it.

Definitely, and I've heard some guys hypothesize that they usually fail around the same time on the truck. Meaning, if you failed at 75k, it'll fail around 150k etc. If that's true, and these failed around 100k, I'm hoping for at least another 20-30k out of it before I have to do them with current mileage at 145k.


I just did the SAC45's on my 02, I'm not opposed to doing SAC00's on this 04, I just don't want to have to do them right away - I need a year or two break before my wallet and my patience tackle that again :roflmao: