SuperwetSC

I have a question about swapping an LS 400 1uz into my 92 sc400. I just want to clarify which 1uz is the right ine to use... I've read that the 90-92 and the 93-94 1uz wiring are different. Out of the two im going to assume that the 90-92 would be the right one (please correct me if im wrong). Sorry for the nooby question I'm trying to get all my ducks in a row before I start buying s*** . Any information would be appreciated! Also, If anybody has done the swap let me know if theres anything I should know before hand.

oldManTan

Why are you swapping?

Ali SC3

iTrader: (10)

You should match the harness and ecu.
If I was swapping an LS400 engine into a sc400, I would use the sc400 harness and ecu to keep things the same.
Do not use the ls400 harness it will complicate things.

also you will need to move over alot of stuff from your old sc400 1uz to the ls400 1uz, the oil filter housings, clutch fan vs hydraulic fan setup.. there are lots of little differences but if you have your old motor you can swap that stuff onto the ls400 one.

SuperwetSC

Im swapping because the upper lower gaskets are blown. Bad compression as well so It's new engine time.

SuperwetSC

But that's the thing.. does that have to be done with any year non VVTI? I've heard that one of the three types was plug n play but that might be false lol. Well, i guess it is for the most part but you get what im saying. If i can get an SC engine i will but the LS400 ones are cheaper for some unknown reason ��

Ali SC3

iTrader: (10)

thats what I said the difference is in the engine harness and ecu, the older years has batch injection which means 2 sets of 4 injectors are paired off and fired together. later years it went to sequential meaning all 8 injectors fire at their own times. when you start mixing the harness and ecu's you get into trouble.

now as far as the engine is concerned, they have the same number of injectors and everything there is no difference there. some earlier years had a cold start injector and you are talking about the same motor, so it would not be difficult to just put the upper intake from your old sc400 motor onto the new one, and it will match the ecu and harness in the car... get it now?

your engine is bad not your ecu and harness. The only other reason to get an earlier year engine pre 96 would be that the motor became interference in 96+ and got a weaker bottom end. this only makes a difference if you are planning on turbocharging or supercharging it though, or if you never like to replace your timing belt. other than that they will all work as said above.

between the ls400 and sc400 there are only minor differences for non-vvti.
mainly the things I said above oil filter housing and cooling system setup and maybe the oil pans might need to be swapped.

SuperwetSC

Yeah I get you. thanks for the info that helps lol

Ali SC3

iTrader: (10)

Yeah just be sure not to junk your old engine and you will be fine for most 1uz no vvti that you can get your hands on. anything that doesn't match you can just swap over to the new one. after its all done and running then junk the parts left over. good time to do a timing belt job, water pump, and coil, rotors, hats, wires, and plugs, and change gaskets to prevent future leaks.