Need help with a LB7 / LBZ conversion truck in SW NY state.

[036.6turbo]

03 LB7 swap to LBZ

My truck is a 2003 CCSB 4wd 2500 DMAX Alli SLT. 336,000 miles. It is going to need a set of injectors soon. (catching a hint of white smoke, 105,000 miles on this set). Instead of putting another set of injectors in, I was considering swapping over to a LBZ. I found an 07 classic work...

www.duramaxdiesels.com

So, I owned this truck from 07 to 18. I did the LBZ swap in 16, sold it to family friends in 18. They live 6.5 hours away.

Fast forward to last week I get a call the truck has died.

Acts like it running out of fuel. Rail pressure codes set, both high and low. (odd, right?)

Current owner replaced the filter head, went so far as to feed CP3 directly with external 9 PSI pump from external diesel source. No help.

I have been on the phone and texting with him. Too much to text here, but it was decided the CP3 has failed.

He replaced the CP3. You guessed it, it still will not run.

Lack of any kind of measurable voltage at the injectors has us questioning if the ECM has left the chat?

Truck is VIN locked to my V2. Idaho Rob tune from the conversion is on my old laptop along with EFILive V8. As of this morning, my laptop and V2 is being shipped to him. Thinking is EFILive with at minimum give him better insight as to with codes are in the ECM. He has been using a handheld scanner, not sure if it's giving the whole picture. Also, if the ECM is bad, any replacement will need those files.

He's kinda of at his wits end. I feel bad for him, every time he opens the hood he's not sure if he's working on a 03 or a 06.

I'm struggling to help trying to diagnose it over the phone. I have never seen an ECM fail, or all (8) injectors stop at once.

Looking for any suggestions on anything we may be missing or is anyone one in that area willing to put a second set of eyes on it?

Pic of it hauling the donor LBZ home.

 

[2004LB7]

Cam and crank are really the biggest one that will keep the ECM from trying to fire the injectors. I'm pretty sure it will try regardless of fuel pressure and RPM

 

[036.6turbo]

Cam and crank are really the biggest one that will keep the ECM from trying to fire the injectors. I'm pretty sure it will try regardless of fuel pressure and RPM

I would expect to see codes for those set?

 

[2004LB7]

I would expect to see codes for those set?

I would expect so. But I've heard it being delayed when it only happens during cranking and not while the engine was previously running. When they receive the laptop, have them look for missing cam and crank counts

 

[036.6turbo]

I would expect so. But I've heard it being delayed when it only happens during cranking and not while the engine was previously running. When they receive the laptop, have them look for missing cam and crank counts

Will do. Thanks.

 

[036.6turbo]

Well, I had hopes with more detailed scanning hardware we could get this running, but that is not the case. My laptop with EFILive shows only the same (2) codes the handheld scanner did. Mass airflow and EGR, EGR is long gone so it's a bit odd that shows up, I would have thought when Rob did the tune, it would no longer set that, but I digress.

I have never used EFILive as a scan tool, only for loading tunes. So trying to talk him through viewing live data while he's 6 hours away is like the blind leading the blind.

But here is what he sent me, Lack of cam impulse readings is concerning?
And a mismatch between crank and number of clyiders.

 

[darkness]

Looks like he selected the wrong module. That’s gasser info looks to me.

 

[036.6turbo]

Looks like he selected the wrong module. That’s gasser info looks to me.

I need to go back and look. It was my assumption when we choose the E38, that was the LBZ ECM. Then the PIDS would present accordingly. But as I said, I'm used to my ICON T10 or GM MDI with GDSII, where you kinda get help from the scan tool knowing what is associated with that VIN.

 

[darkness]

E38 covers gas engines too.

 

[Cougar281]

LBZ would be E35A.

 

[Bdsankey]

As stated, E35A is the LBZ ECM.

If it has no voltage at the injectors it is NOT an injector problem as it would still try to fire them off. It appears that either the ECM is not seeing a condition to fire the injectors or the ECM has left the group chat and cannot fire them.

 

[036.6turbo]

I instructed him to use the drop down and select E35A. He is going to try and add PIDs for cam and crank signal, then try and crank again see if the ECM is getting any input from those.

Thanks everyone.

 

[036.6turbo]

On todays episode of "why won't this start", the correct ECM was selected from the drop down, data PIDs added a record of a cranking event was done. EFILive sees no activity from the ECM. I am beginning to think the ECM is bad.

 

[2004LB7]

Have you verified power and ground at the OBD port?

 

[036.6turbo]

Have you verified power and ground at the OBD port?

I'm not at the truck; it's 6 hours away. I will the guy I'm helping to verify. He did say the V2 lit up, all on its own when he plugged it into the OBD port, so I believe it has power and ground. But I will have him verify.

Thank you

 

[2004LB7]

I'm not at the truck; it's 6 hours away. I will the guy I'm helping to verify. He did say the V2 lit up, all on its own when he plugged it into the OBD port, so I believe it has power and ground. But I will have him verify.

Thank you

That's a good sign. Means OBD has power

Just need to verify signal wires now

 

[036.6turbo]

Well, we choose to reflash the ECM.

It did take a flash, he cranked it, saw some cam sensor pulses.

It didn’t start.

Pulled the codes, same (2) plus two more.

One for VATS, one for fuel sending unit voltage.

Crap, I instructed him to flash the stock tune back in. (Donor truck had dual fuel tanks.)

Somehow the correct tune was in a zip file.

Unzipped it, told him to flash that.

Now it’s hung up. Won’t complete the flash.

Any attempt to abort gives scary error warnings.

Have we bricked the ECM?


Sent from my iPhone using Tapatalk

 

[2004LB7]

I remember there being a check box or button to attempt a recovery. Have you tried that yet?

 

[036.6turbo]

I remember there being a check box or button to attempt a recovery. Have you tried that yet?

Yeah, again. I'm not there.

He has my old laptop and V2 with EFILive V8. I have my current laptop with EFILive V8 running, but without mine being plugged into a truck I am not seeing exactly the same things he is, as I try to walk him through flashing it.

I'll google the recovery option. Thanks for the tip.

 

[Bdsankey]

Worst case pull the module and send it to me. If he wants to save the VIN license send the flashing device as well.

I can attempt a bench flash via SPS and then put his file into it.