LB7=LMM Swap
- Thread starter 1chevy02
- Start date
Have to swap to the LBZ injectors, ECM & TCM, the egr intake to get rid of the butterfly valve, reprogram the GPCM, MAYBE a LBZ engine harness (I'm un-sure of that, as I don't have a LMM wiring diagram on me atm.). Off the top of my head that's about it, but I haven't done much research into it. -- Just to give you a general idea.
Yep, all depends what your time is worth in dollar value to you. Be prepared to be out of the money for a bit though. You're going to as least eat the injectors and computers for a few weeks. Not sure on the demand of stock LMM injectors but it could be awhile before you sale them.
x2, since it is going into an '02, the electrics won't plug-n-play in either case, might as well save some trouble and keep it an LMM.
Yes, that would clearly be the case if he was putting it in a 02. However, he earlier stated it's going into a 04. Offering poor advice because you didn't read his question, isn't going to help anything but make it more difficult for those who know what the hell is going to to explain it.
Not that simple. For starters LMM and LBZ communication protocols are different. LMM ECM actually talks to the truck though high speed. Where as the LBZ ECM & TCM is programmed by high speed and talk to each other in it, but they talk to the rest of the truck low speed. Same reason it's really complicated to put a LLY or LBZ in a 02 and older vehicle. In this case however, the engines (LBZ and LMM) are almost mechanically identical for the most part and can be converted to one another. Now if a LMM TCM and ECM can be programmed to be back to the older O.S. I belief so. However, I don't think it is as simple as EFI live to do this. Last I knew it took bench programming, which is a lot more than the average home user has.
Can you explain why he has to convert it to an LBZ to make it work? Is it just so the computers acan talk to the other computers in the truck?
The injectors shouldn't need to be swapped out BTW. LBZ and LMM injectors are interchangeable. Meaning an LBZ can run on LMM injectors and vice versa.
The injectors shouldn't need to be swapped out BTW. LBZ and LMM injectors are interchangeable. Meaning an LBZ can run on LMM injectors and vice versa.
My bad, he did say an 04. I somehow missed that in his post, and saw an 02 in his signature. No need to get snippy though...
chrisuns is actually right when he says it is how the computers "talk" to the truck. The protocols that the LMM uses to talk to the rest of the truck are different than what the 04-06 trucks use, so if you put the LMM in the older truck it won't be able to communicate. If the computers don't talk to the rest of the truck, thinks like the security system won't work right, and presumably the OP wants the truck to work like factory.
The same reason I mentioned above. -- Those O.S. speak two different languages. Can't leave an open loop in the system either otherwise it will throw codes. The injectors have to be swapped, they're flow matched then programmed into the ECM and GPCM. -- LBZ 6 hole IIRC and LMM are 7 hole, it'll screw the whole injection chart if you interchange these. They know how many holes each injectors has, flow charts ect ect...
With some one who already has EFI live the injection tables in the tunes probably won't be staying stock for long. I'm just saying they will work with an LBZ ECM. Its backwards too, LMM's have one less whole then the LBZ. It really doesn't matter if on flows a touch more then the other (between LMM and LBZ)... If it would matter guys who put bigger injectors in their trucks would be screwed.
Bumping this up....
Im doing a standalone harness for a customer, and he has an LMM engine. Its 100x easier to do standalone with 2001-2007 ECM OS's because cruise control and speedo/tach are configured as discrete signals on the older trucks, as opposed to just being sent as data messages over GMLAN on 2007.5+ trucks.
So Im suggesting the guy buy an LBZ ECM, plug it into his LMM harness (there are a couple minor pin differences, Ill worry about that when I build the harness), and run the LMM as an LBZ.
Its been years (probably 7 years) since I messed around with LBZ/LMM "hybrid" tunes. IIRC the pulsewidth and timing tables were a little different but thats about it. So if I just use LMM pulsewidth/timing tables as a start, copy-pasta them into the LBZ tune.....is there any reason an LBZ ECM wont happily run an LMM (injectors)??
Ill probably just disable the "injector flow values not programmed" codes, because Im not sure if the LBZ ECM/GPCM would properly learn LMM injector values... I doubt thats going to cause a huge issue??
thanks
Ben
Im doing a standalone harness for a customer, and he has an LMM engine. Its 100x easier to do standalone with 2001-2007 ECM OS's because cruise control and speedo/tach are configured as discrete signals on the older trucks, as opposed to just being sent as data messages over GMLAN on 2007.5+ trucks.
So Im suggesting the guy buy an LBZ ECM, plug it into his LMM harness (there are a couple minor pin differences, Ill worry about that when I build the harness), and run the LMM as an LBZ.
Its been years (probably 7 years) since I messed around with LBZ/LMM "hybrid" tunes. IIRC the pulsewidth and timing tables were a little different but thats about it. So if I just use LMM pulsewidth/timing tables as a start, copy-pasta them into the LBZ tune.....is there any reason an LBZ ECM wont happily run an LMM (injectors)??
Ill probably just disable the "injector flow values not programmed" codes, because Im not sure if the LBZ ECM/GPCM would properly learn LMM injector values... I doubt thats going to cause a huge issue??
thanks
Ben
Ben,
I have a 04 lb7 4x4 with engine issues and want to swap to newer engine. I have a local guy selling a LMM with the trans. I see where you say to run it as a LBZ. Can I just use a LBZ wiring harness and do I use the TCM from the trans on the LMM?
Btw, how did that one you did turn out?
Thanks
Jason
I have a 04 lb7 4x4 with engine issues and want to swap to newer engine. I have a local guy selling a LMM with the trans. I see where you say to run it as a LBZ. Can I just use a LBZ wiring harness and do I use the TCM from the trans on the LMM?
Btw, how did that one you did turn out?
Thanks
Jason
Ben doesnt look in on the forum much anymore, so I doubt you're going to get an answer.
Best bet is to PM members "rfletes79" https://www.duramaxdiesels.com/forum/member.php?u=5263 or "RPM Motorsports" https://www.duramaxdiesels.com/forum/member.php?u=1013 and ask them what it'll take.
Best bet is to PM members "rfletes79" https://www.duramaxdiesels.com/forum/member.php?u=5263 or "RPM Motorsports" https://www.duramaxdiesels.com/forum/member.php?u=1013 and ask them what it'll take.
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With lb7's now having sac injectors available, there really isn't much incentive imho to change to a newer engine. If sac's really do stop the injector issue(which I'm banking on as I put a set in mine), then why go through the hassle and expense of changing engines, harness's, and controllers.