Ok, so I am 70k + into a set of replacement injectors, and had a scare with smoke, got it cleaned up, for the time being, but I refuse to buy anymore LB7 injectors. So, I am looking for a donor LLY. When I find it, I will swap heads, injectors, lines, etc. I want to keep everything else as it is. LB7 turbo, etc., I read on here where someone did this swap, and ran it on LB7 electronics? Is this possible in the long run? I know all about the differences in voltage,etc., but my question is, Has anybody logged enough time/miles on one of these swaps to know if it works? If not what is the simplest, easiest fix for the electronics differences? Anybody entertained the idea of a voltage reducer for the lly injectors? I have seen it said, the lly is basically a lb7 block with GM's first attempt at emissions control, so why shouldn't this work? I want a simple truck for driving, moderate towing, etc. I know these old trucks are going away at a fast rate, but I need to drive mine a little longer. I would hate to be 300 miles from home, and have to tear my motor down for injectors in a strange place with no help, just sayin".
LB7 to LLY heads question?
- Thread starter outtatimexx
- Start date
A few people have done the swap. It's much harder to get right but is possible. Much easier on 03-04 trucks.
what year duramax do you have? 01 or 02 i would do it like you said and use the LB7 FCIM to drive the LLY injectors. just swap out the heads, injectors, lines, rail, etc to run the LLY injectors
if 03 or 04 you can damn near just drop in the LLY engine, FCIM and ECM with some minor wiring / pin changes
if 03 or 04 you can damn near just drop in the LLY engine, FCIM and ECM with some minor wiring / pin changes
LLY heads
I thought I had it in my garage, sorry, it's an "02 LB7 180K, in excellent condition, other than crappy injectors! I have read a lot of variations on here, and even the "I seen the impossible" Thread, but I just want to know what will work and work for the long haul. If I need a custom harness, then fine, but If someone has found a good, dependable work-a-round, then I want to know, please. Thanks for your time.
I thought I had it in my garage, sorry, it's an "02 LB7 180K, in excellent condition, other than crappy injectors! I have read a lot of variations on here, and even the "I seen the impossible" Thread, but I just want to know what will work and work for the long haul. If I need a custom harness, then fine, but If someone has found a good, dependable work-a-round, then I want to know, please. Thanks for your time.
If I'm not kistaken, electrically you just need the pigtails for LLY injectors. If you're interested I have a set of cores. And I have 2 heads but they're pending sale of I can ever get my butt to ups for a quote
Anything can be done. I ran my 02 as you describe, Lly with LB7 turbo ficm and ecm. Ran good, a little noisy in the winter but put 40k miles on it like that. No issues, plenty of long trips throughout the yr, 800-1000 mile vacation trips.
Once it came time for smog I installed a modded lly harness and completed the conversion with an lly turbo ficm ecm and egr system. Everything functions as if it came from the factory. No funky noises hiccups or anything. I've put about 10k on it since this last mod.
Either way works good, after driving my truck both ways I would recommend a modded lly harness. It's cleaner and imo runs better, just my 2 cents.
Once it came time for smog I installed a modded lly harness and completed the conversion with an lly turbo ficm ecm and egr system. Everything functions as if it came from the factory. No funky noises hiccups or anything. I've put about 10k on it since this last mod.
Either way works good, after driving my truck both ways I would recommend a modded lly harness. It's cleaner and imo runs better, just my 2 cents.
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Re. LLY heads to LB7
Great! I just got back from a 900 mi. round trip with an almost complete LLY, missing starter, flexplate, and fan mount. Got a few questions, please? Both harnesses with plugs are still on this motor, along with ficm. Smog is not an
issue here where I live, (rural Ga.) . If I run the LLY injectors on the LB7 electronics, can I expect decent mileage, how about smoke? I like to run a PPE excelerator when towing, in the second stage, 50hp. Can I do this? In other words, I am asking if performance will be near normal for an LB7? Will I actually gain anything by Installing the complete LLY? Motor looks really good, just a little rusty in places from sitting. How about the variable turbo? What's involved with using that? I do not have the LLY ecm, but I wound up getting the thing for 1400. Thanks for answering a bunch of dumb questions from a learner.
Great! I just got back from a 900 mi. round trip with an almost complete LLY, missing starter, flexplate, and fan mount. Got a few questions, please? Both harnesses with plugs are still on this motor, along with ficm. Smog is not an
issue here where I live, (rural Ga.) . If I run the LLY injectors on the LB7 electronics, can I expect decent mileage, how about smoke? I like to run a PPE excelerator when towing, in the second stage, 50hp. Can I do this? In other words, I am asking if performance will be near normal for an LB7? Will I actually gain anything by Installing the complete LLY? Motor looks really good, just a little rusty in places from sitting. How about the variable turbo? What's involved with using that? I do not have the LLY ecm, but I wound up getting the thing for 1400. Thanks for answering a bunch of dumb questions from a learner.
Give Russ at RPM Motorsports a call or PM him on here. He has done a lot of these conversions and will have all of the info you are looking for. I don't believe the PPE is going to work for you as it's taken quite a bit of custom tuning with EFI to make the set-up work depending on which configuration you go with.
it is going to take some custom tuning to make it all work and run well. its going to take someone who has messed with LLY injectors on a LB7 ECM/FICM to get it right without spending a lot down time on the truck to make it run like it did as a LB7
I have a low mileage 2004 LB7 that's about to need injectors myself. I want to head stud it as well when I do the injectors so maybe I should go this route myself .
What is actually needed to swap a 04 LB7 over to the LLY setup?? Anyone have a complete list of exactly what's needed or a link where it's been posted in the past?
What is actually needed to swap a 04 LB7 over to the LLY setup?? Anyone have a complete list of exactly what's needed or a link where it's been posted in the past?
01/02
* (LLY using LB7 electronics) I only do this job in house, my cell rings Constantly about this swap. I will not send or sell a tune file. If you need tunes, Rob and I had countless hours into this and he could assist you. It's possible to get running good, but You'll go crazy trying to figure out the tuning on your own. I only use this route for Ca smog reasons now..
* (LLY using LLY electronics) I do with Ben's assistance getting a botched harness figured out in the past, have a harness to use everything LLY in the 01/02 trucks. This is a much easier conversion, and literally plug and play with a custom harness. No tuning drama, and runs with the LLY turbo.
* In Ca., due to the new STAR smog program, this conversion has needed a State Ref certification, OBD2 test sees it as an 03/04 in an 01/02 truck. It's legal but the system kicks it out.
03/04
* Direct swap LB7 to LLY (plug & play).., usually takes us about 10hrs.
* Quickest to install a complete LLY motor with body side LLY harness, LLY ECM & LLY NSBU switch.
* Emergency relearn, or turn VATS off with tuning and your done.
* If you spend time sourcing all the little stuff and convert your LB7.., your going to be 30-40+hrs invested easy..
Russ, with the new STAR program, will I have any problems on getting mine smogged next year? Haven't had any problems the last two smog tests. You did my transplant 4 years ago.
So far the 03+ have not had an issue on the OBD2 side, it's only been the 01/02 with LLY electronics that get kicked back for some reason. Nobody has had an issue with the Ref, they just give a compliance sticker for future smog's. Either way, your conversion is 100% Cali legal because all smog equipment was retained.
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Not trying to hijack thread but what does the LBZ conversion cost? Compared to LLY head conversion
Okay so I've been busy, and just got around to posting again. I have a question. I have read and re-read the I've seen the impossible thread, and I am intrigued by Hawk355's hybrid conversion of an '02. Ie lly heads and injectors running on lb7 electronics. What I'm saying is that some of us would like a moderate approach to a reliable injection system. No frills. What I am asking is this; If an lly injector is considerably smaller than a stock lb7 injector, why couldn't you just substitute 20 or30% over lly injectors to save all the tuning issues with the motor? Anybody made a comparison between the two style injectors? Is there something I am missing?
Been around that bush many times.., if it was that easy everybody would be doing it .. You will literally go nuts trying to figure out tuning on your own. I had help from Rob (ATP) the first time around, and it took us a solid month.. even then, I spent another week fine tuning myself.
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Looking for a tuner or someone with efi v2 in cenral Georgia area?
Need help diagnosing a skip in a 2002 LLY conversion. Been around the bush with this thing. Got new injectors, new engine harness, swapped FICM, checked wiring to ECM, and I need a scanner to diagnose this thing. Anybody out there? Thanks in advance.
Need help diagnosing a skip in a 2002 LLY conversion. Been around the bush with this thing. Got new injectors, new engine harness, swapped FICM, checked wiring to ECM, and I need a scanner to diagnose this thing. Anybody out there? Thanks in advance.