Another Lb7 to LLY question

[Yngdmax92]

having some little problems with my lb7 and just sick of always worrying about my injectors, ever since i put Merchant automotive ones in my truck, they are louder then the originals and the balance rates are all over the place and i just cant see spending another 2000 dollars on injectors if they fail again. i have one going out right now it seems but it goes from 0 one day to 3 to another day. EDGE CS was the worst thing i ever installed, i check them every time i get in my truck.
But any ways, i am in it for the long haul with my truck, i have redone the body, redone the transmission, new rear end, paint and so on. But now i have came a across a lly out of a school bus, it has around 100,000 miles and comes with The ecm, ficm, gpcm and wiring harness on the top of the engine. The questions that i have are

My truck is a 2003, so i know people say it is a Plug and Play, but what exactly do people refer to when they state that unplugging yadda wire from under neath my fuse box and plugging in a lly one? Is this the wiring that goes from the ecm and y's off too the two big connecters over the driver side valve cover?
Also, since i cant tell that the engine runs or not. what do you guys recommend me looking to checking if it is just sitting on a crate?

thanks, any opinions would be greatly appreciated

 

[hondarider552]

If they cant start it for you offer half of what their asking. That's what I have done for every engine I have bought.

 

[Yellow Jacket]

having some little problems with my lb7 and just sick of always worrying about my injectors, ever since i put Merchant automotive ones in my truck, they are louder then the originals and the balance rates are all over the place and i just cant see spending another 2000 dollars on injectors if they fail again. i have one going out right now it seems but it goes from 0 one day to 3 to another day. EDGE CS was the worst thing i ever installed, i check them every time i get in my truck.
But any ways, i am in it for the long haul with my truck, i have redone the body, redone the transmission, new rear end, paint and so on. But now i have came a across a lly out of a school bus, it has around 100,000 miles and comes with The ecm, ficm, gpcm and wiring harness on the top of the engine. The questions that i have are

My truck is a 2003, so i know people say it is a Plug and Play, but what exactly do people refer to when they state that unplugging yadda wire from under neath my fuse box and plugging in a lly one? Is this the wiring that goes from the ecm and y's off too the two big connecters over the driver side valve cover?
Also, since i cant tell that the engine runs or not. what do you guys recommend me looking to checking if it is just sitting on a crate?

thanks, any opinions would be greatly appreciated

I'm guessing the bus chassis harness won't be plug and play for you...

 

[Yngdmax92]

Its mated to a Allison, I will look very close to that and check to see if the harness is the same or not. I have never heard of a duramax in a bus, so I am gonna guess it was one of those chevy van fro n t ends with the rest of the chassis being a bus. I'll take detailed pictures and put them up on here also. Thanks for the quick responses fellas!:thumb:

 

[RPM Motorsports]

If it's from a Bus/Rv/Kodiac it possibly has the wrong oil pan, bell housing, harness and filer head will be on the wrong side. All of these will interchange with your LB7 except for the harness. Some of the Bus/Rv/Kodiac harnesses have the ECM/TCM mounted on the pass side of the vehicle near the firewall. The bale connectors will be located on the pass side as well. The connector under the fuse box is the black rectangle in the center, plus a few small connectors laying in the bottom of the box.

 

[Yngdmax92]

good information ^^^^^ thanks. going to go look at it sometime maybe this weekend or next week. ill post pics soon

 

[Yngdmax92]

How can you physically fell the difference between a lly and lbz if mouth piece is off this engine? It's just the engine on a crate, so I need to make sure that it is lly and not a lbz to make the swap a lot easier.

 

[02greysixer]

A true 04.5-5 lly will have a ficm. 06lly and lbz have no ficm and grid heater looks like this

 

[Yngdmax92]

Wow didnt realize a lbz had no ficm, lol I been studying to much up on lb7 and lly.

 

[Yngdmax92]

Well fellas, the engine indeed is a lly, and like some stated above it is a engine out of the bus. Fuel filter on wrong side, harness is completely different and oil pan is different. None of that concerns me, what does concern me is the fact that the guy has no proof of miles other than he said he bought it from a buddy that had it as a back up engine for his sons truck. States it has around 100,000 miles or so. The engine is literally still sitting in the frame still bolted to the transmission. He bought it for 3k and says he would like to get 2500 out of it. I am going too call him up and let him know I'm willing to give 1000 for just the engine. You guys think that fair? The injectors and fuel lines have a lot of surface rust, so hopefully they don't need to be replaced. If he goes for it, I will be swapping over my lb7 turbo and intake setup to the lly

 

[Yngdmax92]

opinions on this. I got the guy down to 1500 and maybe could inch out a couple more hundred for this lly. Comes compete engine (injectors, pump, turbo and all) with ecm, ficm, gpcm and engine harness(useless for me because it is a bus type harness) doesnt have paper work but states the engine has around 100,000 miles on it. What do you guys think?

Plan is to buy it and pull the pan and put a truck series type on on it. pull one main and which do you guys recommend me pulling? pull the heads, get them pressure checked and maybe a valve job. arp studs, new water pump and put my modded ihi on it with my lb7 intake system on it. Just seeing if you guys think its a good buy or not.

 

[07keo02]

I'm doing somewhat of the same, unfortunately on an 02. Are you comfortable with the LB7 bottom end currently in your truck? I'm just taking my LLY heads/fuel system and putting them on my LB7. Then you don't have to worry about changing anything on the LLY and you can still do studs because it's a head swap.

 

[Yngdmax92]

well, I still have to do a compression test on my original engine and I my keep the short block of the lb7 and build it while I am running the lly for now. my truck Is a 2003 so its all going to be a plug and play for me. there both the same bottom ends and one will be sitting on a stand and will be so much easier to work on versus doing it in the cab.

 

[07keo02]

Makes sense.

 

[Yngdmax92]

do you get your lly in your truck yet? and are you going to do anything while it is out like head gaskets and studs?

 

[07keo02]

The motor I got needs head gaskets so I'll be doing studs. I bought this engine on the cheap so it's missing lots of stuff I need (rails, lines, tcm, ecm). I'm still undecided on the swap. By the time I come up with all the stuff and get the heads checked out I could probably do injectoes and a turbo upgrade on the LB7.

 

[Yngdmax92]

true, and that has crossed my mind too. I plan on driving my truck for another 6 to 10 years so anything is better then having a 500 to 700 dollars payment each month. just trying to stop the nickel and diming part of it right now. it seems every time I get in my truck I am always looking at my edge cs checking balance rates....drives me nuts!!!

 

[07keo02]

true, and that has crossed my mind too. I plan on driving my truck for another 6 to 10 years so anything is better then having a 500 to 700 dollars payment each month. just trying to stop the nickel and diming part of it right now. it seems every time I get in my truck I am always looking at my edge cs checking balance rates....drives me nuts!!!

Yeah, I'm keeping this one as long as possible. I regretted getting rid of my last one so I'm learning from my mistakes. If I just could have ripped all my parts off the other one I wouldn't be starting all over again. I'm thinking about doing injectors and a turbo upgrade, parting out the other engine, and saving up for a full blown LBZ/Allison 6 speed swap. I change my mind way too much though.......