Another LBY swap

rfletes79

Active member
Mar 5, 2010
646
147
43
Galt, Ca 95632
So here we are again, another LB7 to LLY swap. Lets beat this up one more time, but with a slight change.......

I have a 2002 2500 LB7, have owned this truck since new in 2001, was my first duramax truck and it is what inspired my chevelle. Well like every other LB7 in the world this truck likes to eat injectors. 250K later and 5 sets of injectors its time for the swap. As most of you guys know I'm pretty lucky to have Russ nearby for guidance in this swap and I have done a good amount of research on my own. I picked up a 05 LLY from a buddy of mine and am planning on stabbing it this coming weekend, starting tomorrow. I know there are a couple different routes in making this happen but want to share a slightly different approach, that so far has checked out well.

I plan on using my current LB7 ECM and FICM to control the LLY, which means I will also use the LB7 turbo. So far Russ has done this swap by making his custom injector harness-adapters to make his happen. Pretty straight forward, use the lly injector plugs on the lb7 engine harness. The other option, also on this site, is to un pin the lb7 injector harness from the FICM and pin in the lly injector harness directly to the lb7 FICM. Either way you end up with a clean install.

The other option is to use a custom harness like the one Ben makes and run the lly with lly controls and with the lly turbo.

The twist............ Why cant we just leave the lly engine harness on the lly motor?? Just plug in the lb7 ecm to it and the lb7 FICM, re-tune and send it on its way........ everything lines up and fits, no adapting, no splicing just plug in your controllers, tie up the un-used plugs (egr, turbo vane sensor etc..) re-tune the ECM to control the LLY injectors and go.

Possible, yes I think so!!! See the attached video. Just fired up my LBY on my engine stand prior to installing it in my truck. The motor is untouched and has the factory LLY harness, LB7 FICM and an LB7 ECM. Tuning still needs to be tweaked slightly (has a lope at idle) but other then that it is good to go.

The real test will be in the truck with the chassis harness, hopefully we'll know this weekend. :)


https://youtu.be/zMfGNFNea60
 

rfletes79

Active member
Mar 5, 2010
646
147
43
Galt, Ca 95632
The above motor is being ran with a stand alone LB7 harness and still has all the factory LLY turbo/egr/y bridge on. I will be removing those components and switching to LB7 tomorrow then installing in my truck.
 

hondarider552

Getting faster
May 28, 2008
10,627
2
36
34
Arizona
I started reading this was got excited but then saw it was in a 2001 :eek:

Pretty different from my LBY swap in my 03 which is plug and play.

I got everything LLY related, LLY ECM,FICM, body harness and trans NBSU that I just swapped out yesterday.
 

rfletes79

Active member
Mar 5, 2010
646
147
43
Galt, Ca 95632
Here's the update, started the swap Friday night after work. Had the old motor out by morning Saturday. Swapped ficm, ran a new fuel line to the filter head, ihi turbo, up pipes, down pipes, routed the turbo coolant lines, installed the federal y bridge..... Had this done by mid day then slammed her in. Stopped sat night after stabbing the motor. Finished today with the swap. Fired it up with the stock 02 lb7 tune, once confirmed that it would run loaded the new EFI LBY tune and didn't turn back. Topped her off with liquids and took her for a test drive. Runs great, best thing I've done to this truck since I bought it brand new in 2001.

So yes, an lly engine harness will work in these swaps (01-02 lb7). No cutting, adapting or splicing. Just plug in your truck side lb7 bail connectors to the lly engine harness do the other swaps/mods to the lly motor and tune then drive.

http://www.youtube.com/watch?v=wrXaraoxu0o
 

rfletes79

Active member
Mar 5, 2010
646
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43
Galt, Ca 95632
2 issues I ran into that need to be addressed. One is the oil pressure, doesn't read right on the dash. The other is the gpcm main power isn't wired in. The lb7 cable doesn't plug in like the lly one. I'll just need to make those 2 corrections to get it dialed. Other then that this would be a pretty straight forward swap for a federal truck out there.

These 2 issues are not major at all and will be fixed, just wanted to point them out for anyone who was wondering or is sceptic of the swap.
 

07keo02

New member
Oct 5, 2011
399
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0
Phoenix, AZ
I was curious how the oil pressure reading would work out on an 01-02 truck. With my swap and Ben's harness I will be running two sensors. One will be for the dash which will read higher because the location on 01-02 trucks. The other sensor will be in place of the 03+ trucks and will read lower when scanning.
 

RPM Motorsports

smokinum
May 13, 2008
3,271
10
38
Central Valley Ca.
Don't remember the PIN number, but it's brown wire. Run the wire down to the 01/02 psi switch and the gauge will work.

Watched Rick fire her up for the first time today.. Using the 01/02 body side LB7 harness, lb7 turbo, FICM, gpcm and litterally plugging the Lly harness in and firing it up on the stock LB7 tune. Going this route the Lly EGR and lb7 intake heater (Fed lb7 bridge used) were not utilized.. It does take custom tuning, as the stock lb7 tune will only work at idle.
 
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rfletes79

Active member
Mar 5, 2010
646
147
43
Galt, Ca 95632
8316a636b05c9aab55703fd198a4ce0f.jpg


Latestest update since the swap 2 yrs ago and 40k miles later. Finally got around to completing the LLY conversion on my 02. Thx to Russel (yellow Chevy) for the turbo.

LLY turbo with wetzel wheel, s&b mouthpiece and intake, triple disk converter, and a modded LLY harness for an 01-02 (modded by me). Truck is quieter, smoother and more powerful then before!!


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outtatimexx

New member
Aug 21, 2017
21
0
1
Perry, Ga.
re. lly engine swap to '01 truck

Hi; I am new here, with a few posts. I have some questions about the swap you did on the '01 truck with the lly motor. I am still mulling what to do with my '02 GMC. at 180k, with 70k on gm replacement injectors, i had a smoke problem. Did the Seafoam trick with 10 gal. fuel and 4 cans, and truck has cleaned up. No smoke. I am running Lucas in every tank of fuel now, and all seems ok. Well, I see this as an omen, and I have searched high and low for answers, here and other places. Thought first about sac style injectors, but If I spend that $ and still have to reprogram with efi live, then why not just repower, at least the heads with LLY and solve the injector location problem as well. So I looked, and looked, and finally may have found a motor for 2k about 6 hrs. away. Story on motor, according to seller, is water in fuel damage at a station, injectors replaced, still ran rough, so motor was replaced. 100k on motor. No way to check motor before purchase. He says everything is there except flexplate. 2k. Should I buy with idea of swapping heads,injectors, or just do the whole swap? Let me say this , I am 67, a career mechanic, have no desire to go fast, do burnouts, blow smoke, etc. I just want to drive it normally, pull my fiver, and expect it to last. Thing is, it looks as if either way I go, I am looking at a minimum of 3k. Thoughts? Thanks for your time
 

rfletes79

Active member
Mar 5, 2010
646
147
43
Galt, Ca 95632
Lly is the way to go. Lmk if there is anything I can do to help you out. You will need a modded LLY harness, which I can do in house. Custom tuning to get the Lly to function properly in your 01. Nsbu switch, and the entire top of the lly engine. Including all brackets and bolts, hoses and piping. Having all this will make the swap so much easier.

2k seems ok as long as all the parts are usable. If your only getting core stuff then only pay core value.

Give me a call if you have any questions.

Rick

2099869706
 

rfletes79

Active member
Mar 5, 2010
646
147
43
Galt, Ca 95632
Well pulled the trigger on a 6 speed conversion for my 02. Should have done this a decade ago. Works extremely well, very happy with it.

It’s a DT kit, other then the delay in ordering and shipping it’s been good. Need to get a retune for the 4-5 and 5-6 shift but not a huge issue. I have it set up to deactivate 5 & 6 in TH mode. And for it not to shift to 6th until 69mph, just don’t need 6th at any speeds below that.


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