1JZ swap problems, please help!!

[TwinTurboMKIII]

hey guys, im balls deep in my MKIII supra 1JZ swap and have most of the main things done, but im still at a loss for what to do with a couple things. please help!

1. Speed sensor- the 7MGTE has an analog speed sensor and thus an analog speedo cable. My 1JZ has a digital sensor on the tranny where the cable SHOULD go. But it doesnt. Will a 7M speed sensor fit on the 1j tranny where the digital one is?

2. Everywhere I have read about these swaps it says that the ECU harness must be lengthened, but i read somewhere else the harness has all sorts of problems after lengthening. and also, i could be mistaken but it looks like my harness might even be long enough to get to the ecu behind the glovebox??

if you have done this swap or know someone who has, please let me know. im so close to finishing my supra and i just want to make sure everthing is done right. Thanks.

 

[JAYspec]

the harness DEFF. needs to be extended. & the only problem u might run into is that the temp gauge reading wrong.

 

[NewGen]

hey guys, im balls deep in my MKIII supra 1JZ swap and have most of the main things done, but im still at a loss for what to do with a couple things. please help!

1. Speed sensor- the 7MGTE has an analog speed sensor and thus an analog speedo cable. My 1JZ has a digital sensor on the tranny where the cable SHOULD go. But it doesnt. Will a 7M speed sensor fit on the 1j tranny where the digital one is?

2. Everywhere I have read about these swaps it says that the ECU harness must be lengthened, but i read somewhere else the harness has all sorts of problems after lengthening. and also, i could be mistaken but it looks like my harness might even be long enough to get to the ecu behind the glovebox??

if you have done this swap or know someone who has, please let me know. im so close to finishing my supra and i just want to make sure everthing is done right. Thanks.

The harness does need to be extended. I think about 18inchs but dont quote me on that. I would just make sure you match up all the guages of wires so there the same. I'm not sure about the speed sensor question but I will try to find it and get back to you.

 

[JonoTurbo]

The entire harness does not have to be extended, there are other options that work. For example, in several swaps i've done, only the body harness connectors have been extended, the ECU plugs do not (which saves you the bulk of the work). There is a catch to this though, you have to drill a new hole in the firewall and perform a 'dash tuck' with the harness to get the ECU into the stock location.

As for the speed sensor, you simply remove the digital one and connect the cable in its place. The only speed sensor on the transmission in the ma70 is on the other side, and it's for the ABS.

 

[supra1008]

The only thing you have to do with body harnesses is cut the ignitor connector off the 1j harness and solder it on to the 7m harness. I just finished doing this. My car is running fine now. Empera will agree with me on this. He helped me with this. The engine harness will have to be extended. Make sure your solder jobs are good or else you will have problems in the future!

The shop that did my engine swap two years ago fucked everything up. They extended and put the 1j body harness in my car. They extended the engine harness too. They didn't do a good job with anything. Also make sure you wrap the engine harness good to protect it from heat. I'm paying for their fuck up now! Take your time and do it right!!!

 

[staticpage]

I had a 1jz out of a jzz30 and just ran the harness a more direct path not up and over then down. Removed some of the plastic on the back of the harness to allow room. I did not extend it at all. Fits fine no rubs and it's now tucked.

 

[Evilempire1.3JZ-GTE]

No do not cut the ignitor connector infact dont cut the junction box#2 connector by the ignitor just unclip the connector off of the JDM junction box & plug it in then you only have to splice 1-2 wires there at the max!

You will have to add the two thick wires that come off the alternator to re-reroute them to the old shorter 7m alternator thick wire connector.

Do not cut or extend the 1JZGTE harness dont even think about it unless your an engineer better then toyota factorys and know how to stagger & do mil or ansi/nasa spec splices if in dought just get all new proper length teflon wires and new connectors if you must do it right otherwise just make the speedo cable a little bit larger cut the back plastic harness tubing where it comes off from the back of the engine so the wires go streight out the back instead of pointing up off the back of the engines, mount your map sensor on the back of the plenum to the bolt where you plastic used to be that you cut off.

as far as the speedo keep the mechanical speedo remove the electrical pickup/sensor

only route the pink wire from the ecu to the speedo output from your gauge cluster pink also only connect them if your car is AUTO otherwise you could leave it disconnected it might flash a ecu speed signal code but you will eliminate the speed limiter built into the ecu.

once you mount your ECU in factory location simply splice the 7M engine side EFI connectors to the 1JZ body side connectors small jumper harness only about 12" long and only about 12-25 wires depending on options like AC cruise oil level sensor etc...

also in your jumper harness make sure to splice together the NSM if your supra was auto and your putting in a manual trans. also make sure to splice your heater control valve wire into the middle of your jumper harness then your done drive and enjoy you could do the swap and be done doing this in less then a week.

Price a new 1JZ harness 7-800 usually not instock + price a new 1JZ ecu maybe even a new motor if you dont do propper shield jumper/splices to the knock & sync signal sensors wires its not worth ruining a factory harness or 1jz being down the extra time or spending wasting money and time extending the harness.

This method works so well me & my brother swapped a soarer engine into a sc400 in under a week the connectors even match physicaly and are electricaly layed out 90% correct we had to drill a completely new hole but we did it at about the same spot as where the supra speedo hole is and it worked perfect.

 

[Guyana00]

[]....just make the speedo cable HOLE a little bit larger cut the back plastic harness tubing where it comes off from the back of the engine so the wires go streight out the back instead of pointing up off the back of the engine....[]

Not being a dick because you forgot the word. I'm pointing it out to the OP as it seems he may be inexperienced and may get confused saying to enlarge the speedo. Especially since he has a problem with his speedo as it is.

So to clarify. Enlarge the hole your speedo cable come into the cabin in (behind the cluster) and run the harness through there and send the harness to the glovebox area. Mount your ECU, plug gthe plugs in. Hint: mount the ECU so the receiving end faces the plugs coming to it.

As for your speedo, take off the converter on the tranny and screw on your speedo cable. Only other things that could be on there are ABS speed sensor and reverse light switch. That should be it.

It doesn't sound like you can, so don't try to lengthen the harness. I couldn't either and I'm not going to. Much less work, I'm not skilled enough to do it for me to be happy with even if it works, some of the wires are shielded. 6 from what I remember. And lastly, there's no need to do it from my research, so why do something unnecessary.

 

[silversup]

Hit up Dr. Tweak..nuff said

 

[TwinTurboMKIII]

damn guys, thanks alot, i didnt think anyone would respond. i really appreciate the help. If this was just a b-series swap into a honda i would have been done in a day but im new to toyota and im trying to stick with it cause i know its gonna pay off in the end.
thanks again for all the help, if i run into anymore problems i'll let you guys know.

 

[SupraStardom]

You can cut the hole that mention earlier. Or you can do as did with mine and buy an extension harness. I bought mine from www.boomslang.us I think it was $175? Dont quote me on that price though. Our 1jz ecu is the same as an OBD 1 Honda/Acura NSX. They made an extension and it was plug and play. I got the body plug jumper harness from aaron at driftmotion for i think $65 and it started no problem first try after i primed the fuel.

Those aren't the best pictures in the world thanks to my amateur shots and crappy iphone camera, but you get the idea. The harness run just long enough to get the plugs in through the firewall and plug into the extension. then your extension runs the rest of the way to the stock ecu mounting location. I took the brackets off my 7m ecu and screwed them on the 1jz one and it was like usdm stock.

 

[AfterDark]

You can cut the hole that mention earlier. Or you can do as did with mine and buy an extension harness. I bought mine from www.boomslang.us I think it was $175? Dont quote me on that price though. Our 1jz ecu is the same as an OBD 1 Honda/Acura NSX. They made an extension and it was plug and play. I got the body plug jumper harness from aaron at driftmotion for i think $65 and it started no problem first try after i primed the fuel.

Those aren't the best pictures in the world thanks to my amateur shots and crappy iphone camera, but you get the idea. The harness run just long enough to get the plugs in through the firewall and plug into the extension. then your extension runs the rest of the way to the stock ecu mounting location. I took the brackets off my 7m ecu and screwed them on the 1jz one and it was like usdm stock.

Has any1 else tried this?

 

[SupraStardom]

I made a thread about it a long time ago, but this route is kinda like the path less traveled. I'm not sure how many others have done it. It works for me though. I like it because with the extension I now have a somewhat disposable solution for wiring in things to the engine harness without hacking my 1jz harness. Ill have to get better pictures than those. Its just that if i put the extension in place it cant be seen, so i had to actually plug it in out side of the firewall to show it actually plugs in and everything

 

[staticpage]

with that extension you would have ecu connections open to weather conditions. i would seal it some how. its a big eye sore as well.

 

[AfterDark]

with that extension you would have ecu connections open to weather conditions. i would seal it some how. its a big eye sore as well.

Unless I mis-read he just pluged it in like that just to show it works. Simple yet effective :love:

 

[SupraStardom]

yea it runs the same. the extention is on the cabin side of the firewall. you just slide your boot up to the end of the harness and use it seal the hole like normal. Its not an eye sore because you will never see it.

 

[RPSil13]

extension

VERY interested in trying this, do you know the part # you purchased, i visited the website and under extensions in the drop down menu it shows Factory Harness Extension Honda/Acura OBD1 but doesnt say how long it is, any help would be greatly appreciated.

thanks

 

[SupraStardom]

It wasnt on the website. i saw they did harness extensions plug and play so i emailed them about the 1jzgte. They asked to see pics of the connectors. I sent them the pics, they replied it was a OBD1 Honda NSX plugs. They sent me the harness 18" i think. I plugged it in and started right up no problems. I like it alot. I can splice into this extension vs hacking my 1jzgte harness.

 

[staticpage]

oh I see, that would be great then. I have read some where that the nsx has same connectors

 

[SupraStardom]

Yeah i think it might have been a thread i started along time ago about this. I started a thread on this but got into some medical stuff and was away from sm for awhile so i never finished it. this is good enough i guess. All that was missing were a few pics, but its hard to take pics of it in place.