95-97 SC3 1JZ swap starting/3K issue solved!
#1
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***UPDATE 4/27/12***
Rev issue for automatic swaps im pretty sure is solved, more info on that below. Some of the pictures i was borrowing have vanished so i snapped a few today while i was re-wiring/cleaning/removing ECM. I still need a pic of a manual 1JZ body plug so i can make all the pics complete so if you're in the middle of yours PM me so i can get this write up as complete as possible.
***
I'm sorry i've been holding back for so long, but i needed all my info right and also needed my car for pics. I still need some pics for a more complete write up so if you have any please PM me them so i can add them appropriately. Anyways here's the run down:
for the 95-97 5 speeds swapping in a 1JZ (manual, auto, and auto-to-manual conversions) there is a problem that arises when you first hook up the battery...the car all of a sudden starts to turn over on its own, no key in the ignition, nothing. Even if you bypass this problem by rewiring your starting circuit, you're left with another problem: the car won't rev past 3000 rpm. This is solved by cutting a wire on the engine harness (pass. side next to the ECU, where the engine harness connects to the body). Depending on the way you wired your starter, you car may not start after cutting this wire. that's when i realized that BOTH THESE PROBLEMS ARE CONNECTED. What's happening is the starter relay circuit wires for the 1JZ are different than the car's original starting circuitry. It's getting supplied 12V and kicking on the relay when you hook up the battery. If you bypass this by rewiring your starter circuit, that same wire is also supplying a constant 12V to the ECU telling it that it's trying to start. By supplying the ECU with the 12V, it limits the revs to 3K until that power is cut off.
With this fix it will remove the sudden start issue and sends the proper signal to the ECU while it's starting. This fix has a bit of a bonus, as it retains your stock clutch safety switch. So enough techno babble, let's fix this ****!!!
DISCLAIMER: i am confident this will work, however, I WILL NOT BE HELD RESPONSIBLE IF YOU MESS UP YOUR CAR!! with that we begin....
for the directions there are variations between setups, so i'll try to organize them to narrow down your setup.
1) Dissconnect the negative terminal on your battery (duh...)
2) go under the pass. side carpet where the engine to harness connections reside.
Part A (for 1JZ originally manual): there is a white plug that sits under the orange plug. Look for a black wire with a white stripe on it (i don't have a good pic and don't know which pin it's located, but there should just be one black wire/white stripe. If you have a pic please PM me so i can add it to this write up). Cut that wire, tape the ends, and tuck them out of the way (this is because the body side of the wire is supplying 12V so make sure it's not touching ground).
Part B (for 1JZ originally auto converting to maunal): Look for the white plug next to an orange plug. It shouldn't have that many wires in it.
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/Wiring1.jpg)
there should be a black wire in pin #10 (in the pic it's the top row, 2 from the left. If you look closely on the plug it has a #10 printed on top of the pin) cut that wire, tape off the ends and tuck them out of the way (this is because the body side of the wire is supplying 12V so make sure it's not touching ground).
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/Wiring2.jpg)
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/000_0031.jpg)
^^ this is just to show the color of the wire. If you look, this wire is in the wrong pin right now. I removed the end of the wire from pin #10 and relocated this wire to pin #24 of the same plug. I then grounded this wire in order to get my temp gauge working.
Part C (for 1JZ auto swap): follow the same instructions as stated above. After you clipped the wire, go ahead and hook up your battery. It should not start on its own. Turn the car on and try to start the car. When it gets going, make sure it revs past 3K RPM with no issues. You should be done at this point, if you have problems PM me.
4) For you manual trans. guys, after you've done your rewiring move into the engine bay over to the main relay box (driver's side in front of the strut tower)
open up the relay box and remove the 2 10mm bolts and one 12mm nut (the one that sits under the + cover). take out the relay box and remove the black plastic cover.
5) looking underneath the starter relay pins, look at pin #2 (schematic labeled on the top of the relay).
For a 95-96 SC it should be a black wire w/ a white stripe
For a 97 SC it should be a green wire with a red stripe
6) taking a long piece of wire (needed for later) and splice it into the wire mentioned above. You can go several ways about this, either solder in the wire or put a small spade connector on the end and shove it into the under side of the pin. The latter mentioned makes it a bit harder to put the relay in, but it works. I went a step further and crimped it into the existing pin. If your good with connector pins i suggest this method, otherwise just solder in the splice. Here's a pic with what i did, my wire is the red one that joins with the green wire:
![](http://i25.photobucket.com/albums/c88/Attiman/0616101938.jpg)
7) Following biggu's NSS bypass thread, run that wire out the fuse box, into the fendwell and into the pass. compartment. You'll need to remove part of the fender well plastic in order to run this wire. I just poked a small hole in the boot where the harness enters the passenger compartment. pics from biggu's NSS thread here: https://www.clublexus.com/forums/per...with-pics.html
![](http://i18.photobucket.com/albums/b107/2zumeunos/SC300/wiring%20for%20NSS/IMG_0967.jpg)
![](http://i18.photobucket.com/albums/b107/2zumeunos/SC300/wiring%20for%20NSS/IMG_0968.jpg)
![](http://i18.photobucket.com/albums/b107/2zumeunos/SC300/wiring%20for%20NSS/IMG_0969.jpg)
8) Look behind the clutch pedal for a button. This is your clutch saftey switch. Behind it is a connector. Dissconnect it.
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/Wiring3.jpg)
9) there should be two wires on it. one of those needs to be cut and soldered to the wire you just run from the engine compartment
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/000_0030.jpg)
for 95-96 SCs, cut the black wire w/ white stripe and solder the CONNECTOR side to the wire you've run into the engine bay
for 97 SCs cut the green wire w/ red stripe an solder the CONNECTOR side to the wire you've run into the engine bay.
Put your fuse box back together, hook your battery back up and test it out. Try to start the car w/o touching the clutch and again depressing the clutch. It should work as it did before the swap. You are now done!!
Any questions or concerns post up or PM me.
Rev issue for automatic swaps im pretty sure is solved, more info on that below. Some of the pictures i was borrowing have vanished so i snapped a few today while i was re-wiring/cleaning/removing ECM. I still need a pic of a manual 1JZ body plug so i can make all the pics complete so if you're in the middle of yours PM me so i can get this write up as complete as possible.
***
I'm sorry i've been holding back for so long, but i needed all my info right and also needed my car for pics. I still need some pics for a more complete write up so if you have any please PM me them so i can add them appropriately. Anyways here's the run down:
for the 95-97 5 speeds swapping in a 1JZ (manual, auto, and auto-to-manual conversions) there is a problem that arises when you first hook up the battery...the car all of a sudden starts to turn over on its own, no key in the ignition, nothing. Even if you bypass this problem by rewiring your starting circuit, you're left with another problem: the car won't rev past 3000 rpm. This is solved by cutting a wire on the engine harness (pass. side next to the ECU, where the engine harness connects to the body). Depending on the way you wired your starter, you car may not start after cutting this wire. that's when i realized that BOTH THESE PROBLEMS ARE CONNECTED. What's happening is the starter relay circuit wires for the 1JZ are different than the car's original starting circuitry. It's getting supplied 12V and kicking on the relay when you hook up the battery. If you bypass this by rewiring your starter circuit, that same wire is also supplying a constant 12V to the ECU telling it that it's trying to start. By supplying the ECU with the 12V, it limits the revs to 3K until that power is cut off.
With this fix it will remove the sudden start issue and sends the proper signal to the ECU while it's starting. This fix has a bit of a bonus, as it retains your stock clutch safety switch. So enough techno babble, let's fix this ****!!!
DISCLAIMER: i am confident this will work, however, I WILL NOT BE HELD RESPONSIBLE IF YOU MESS UP YOUR CAR!! with that we begin....
for the directions there are variations between setups, so i'll try to organize them to narrow down your setup.
1) Dissconnect the negative terminal on your battery (duh...)
2) go under the pass. side carpet where the engine to harness connections reside.
Part A (for 1JZ originally manual): there is a white plug that sits under the orange plug. Look for a black wire with a white stripe on it (i don't have a good pic and don't know which pin it's located, but there should just be one black wire/white stripe. If you have a pic please PM me so i can add it to this write up). Cut that wire, tape the ends, and tuck them out of the way (this is because the body side of the wire is supplying 12V so make sure it's not touching ground).
Part B (for 1JZ originally auto converting to maunal): Look for the white plug next to an orange plug. It shouldn't have that many wires in it.
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/Wiring1.jpg)
there should be a black wire in pin #10 (in the pic it's the top row, 2 from the left. If you look closely on the plug it has a #10 printed on top of the pin) cut that wire, tape off the ends and tuck them out of the way (this is because the body side of the wire is supplying 12V so make sure it's not touching ground).
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/Wiring2.jpg)
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/000_0031.jpg)
^^ this is just to show the color of the wire. If you look, this wire is in the wrong pin right now. I removed the end of the wire from pin #10 and relocated this wire to pin #24 of the same plug. I then grounded this wire in order to get my temp gauge working.
Part C (for 1JZ auto swap): follow the same instructions as stated above. After you clipped the wire, go ahead and hook up your battery. It should not start on its own. Turn the car on and try to start the car. When it gets going, make sure it revs past 3K RPM with no issues. You should be done at this point, if you have problems PM me.
4) For you manual trans. guys, after you've done your rewiring move into the engine bay over to the main relay box (driver's side in front of the strut tower)
open up the relay box and remove the 2 10mm bolts and one 12mm nut (the one that sits under the + cover). take out the relay box and remove the black plastic cover.
5) looking underneath the starter relay pins, look at pin #2 (schematic labeled on the top of the relay).
For a 95-96 SC it should be a black wire w/ a white stripe
For a 97 SC it should be a green wire with a red stripe
6) taking a long piece of wire (needed for later) and splice it into the wire mentioned above. You can go several ways about this, either solder in the wire or put a small spade connector on the end and shove it into the under side of the pin. The latter mentioned makes it a bit harder to put the relay in, but it works. I went a step further and crimped it into the existing pin. If your good with connector pins i suggest this method, otherwise just solder in the splice. Here's a pic with what i did, my wire is the red one that joins with the green wire:
![](http://i25.photobucket.com/albums/c88/Attiman/0616101938.jpg)
7) Following biggu's NSS bypass thread, run that wire out the fuse box, into the fendwell and into the pass. compartment. You'll need to remove part of the fender well plastic in order to run this wire. I just poked a small hole in the boot where the harness enters the passenger compartment. pics from biggu's NSS thread here: https://www.clublexus.com/forums/per...with-pics.html
![](http://i18.photobucket.com/albums/b107/2zumeunos/SC300/wiring%20for%20NSS/IMG_0967.jpg)
![](http://i18.photobucket.com/albums/b107/2zumeunos/SC300/wiring%20for%20NSS/IMG_0968.jpg)
![](http://i18.photobucket.com/albums/b107/2zumeunos/SC300/wiring%20for%20NSS/IMG_0969.jpg)
8) Look behind the clutch pedal for a button. This is your clutch saftey switch. Behind it is a connector. Dissconnect it.
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/Wiring3.jpg)
9) there should be two wires on it. one of those needs to be cut and soldered to the wire you just run from the engine compartment
![](http://i25.photobucket.com/albums/c88/Attiman/Wiring%20pics/000_0030.jpg)
for 95-96 SCs, cut the black wire w/ white stripe and solder the CONNECTOR side to the wire you've run into the engine bay
for 97 SCs cut the green wire w/ red stripe an solder the CONNECTOR side to the wire you've run into the engine bay.
Put your fuse box back together, hook your battery back up and test it out. Try to start the car w/o touching the clutch and again depressing the clutch. It should work as it did before the swap. You are now done!!
Any questions or concerns post up or PM me.
Last edited by StiCk3; 10-07-12 at 03:57 PM.
#2
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very fking thorough man. i'll keep this in mind for future references. i don't come on often to comment cause creeping is more fun. i'm going to link this in my "all 1jz swap questions answered" thread. is that alright?
#3
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and yea i had to be thorough in order to get this right. Wasn't fun digging through this stuff, but one night it hit me that there was a relation between the 3K issue and this starting problem. Its simple once u understand a wiring diagram...
#4
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Are you kidding?? I know you and you didn't fix I at all??? It's still having problems and has gotten worse, especially the jumble of wires you have in there underfur kick panel!! I font think this guy is all he says he is cracked up to be, especially no ASE's and then he talks like he knows what he's doing around the shop
Last edited by mrsayaovon; 07-05-10 at 01:21 PM. Reason: Typo
#5
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I know you and that didn fix your car at all!!.... It still sits in the back of the shop and it runs worse!! Almost as if you have now given up on it, cmon, really!
#6
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The wires under the dash is the ECU wiring because im sourcing an issue with my A/C.
As for experience, no im not an expert, but i have 4 ASEs just waiting for the last two months of experience before it's official. Anything other bones you have to pick with me take it to my PM box.
And no you don't know me
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Last edited by StiCk3; 07-05-10 at 06:14 PM.
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Good job on the thread. I've been meaning to get a video up for this that explains the whole fix for other people but I just got lazy. Thanks for the contribution,
TO OTHERS: please do not put this gentlemen down regardless of what he is outside of the forums, he has contributed to a lot of owners who own 1996 models. These model years have slightly different wiring and don't have too much resources on the forum on their fix when doing 1jz swaps, he is nice enough to go out of his way to give a thorough write up.
TO OTHERS: please do not put this gentlemen down regardless of what he is outside of the forums, he has contributed to a lot of owners who own 1996 models. These model years have slightly different wiring and don't have too much resources on the forum on their fix when doing 1jz swaps, he is nice enough to go out of his way to give a thorough write up.
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#8
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Good job on the thread. I've been meaning to get a video up for this that explains the whole fix for other people but I just got lazy. Thanks for the contribution,
TO OTHERS: please do not put this gentlemen down regardless of what he is outside of the forums, he has contributed to a lot of owners who own 1996 models. These model years have slightly different wiring and don't have too much resources on the forum on their fix when doing 1jz swaps, he is nice enough to go out of his way to give a thorough write up.
TO OTHERS: please do not put this gentlemen down regardless of what he is outside of the forums, he has contributed to a lot of owners who own 1996 models. These model years have slightly different wiring and don't have too much resources on the forum on their fix when doing 1jz swaps, he is nice enough to go out of his way to give a thorough write up.
As for the guy bashing me above, it was a co-worker of mine that was just screwing with me so disregard his remarks.
#13
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i really dont like how that looks. toyota put that relay there for a reason.
------------------------------------------------------------------------
alot of people that seem to do the swap on here. just swap out the trans on their 2jz or 1jz and make everything work with that trans.
but as far as i can tell. since 1j Soarer swaps with a manual trans seem to be rare on this site. no one has put up a proper swap guide.
#14
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i dont think they are sharing. the only way i can get it to start is jumper 2 and 5 on the relay with a fuse and a wire ran straight to the thick gauge black and white wire on the ignition switch.
i really dont like how that looks. toyota put that relay there for a reason.
------------------------------------------------------------------------
alot of people that seem to do the swap on here. just swap out the trans on their 2jz or 1jz and make everything work with that trans.
but as far as i can tell. since 1j Soarer swaps with a manual trans seem to be rare on this site. no one has put up a proper swap guide.
i really dont like how that looks. toyota put that relay there for a reason.
------------------------------------------------------------------------
alot of people that seem to do the swap on here. just swap out the trans on their 2jz or 1jz and make everything work with that trans.
but as far as i can tell. since 1j Soarer swaps with a manual trans seem to be rare on this site. no one has put up a proper swap guide.