You can use any 1g awd trans as long as you use a 1990 shift cable bracket, also you can use a 91 ecu if you switch pins 14 and 6 I believe.

a few plugs are different like the cas throttle body and coil pack i put a 90 motor in my 91 it took a few changes i have a few 90 parts left over if u need let me know i will let them go for cheap

tcb1 said:

a few plugs are different like the cas throttle body and coil pack i put a 90 motor in my 91 it took a few changes i have a few 90 parts left over if u need let me know i will let them go for cheap

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Would you happen to have 90 shift cable brackets?

tcb1 said:

a few plugs are different like the cas throttle body and coil pack i put a 90 motor in my 91 it took a few changes i have a few 90 parts left over if u need let me know i will let them go for cheap

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Can i just wire in the plugs from my 91 to the 90 harness or do i need new sensors?

blaster1812 said:

You can use any 1g awd trans as long as you use a 1990 shift cable bracket, also you can use a 91 ecu if you switch pins 14 and 6 I believe.

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So i dont need to replace the shifter cables if useing a 91 trans?

And also with switching the pins you mean putting wire 6 into 14 and 14 in 6 right?

I would swap the ECU and harness from the 91 to the 90 (maybe lose the cruise control while you're at it or swap that one too from the 90).
If the transmission is from a 91 up I would also swap the shifter assembly and cables from the 91. Make sure you use the correct transfer case too.

im not sure on how the wiring would work for the cas and whatnot google is the best answer for that i might have the 90 shifter bracket id have to look for it tho

tcb1 said:

i might have the 90 shifter bracket id have to look for it tho

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That would be awesome. Let me know if you have it, I'll paypal you same day.

If you use the 91 engine harness in the 90 there are some body connectors that are different as well.
And to add to the shift linkage info you will more then likely need to switch selector arms on the tran as well ast the linkage bracket depending what year the tran is. 90 cables, shifter base and selector arms are completely different from the 91-94 models......I just went through this whole ordeal.

I also have the shifter base and cables for a 91+ transmission if you want to go that route.
I'll get ya some good prices on them.

Also not sure if the car already has a 255 Walbro.

If you need any help when your putting it together let me know Ill try to help ya out.

buhay6 said:

If you use the 91 engine harness in the 90 there are some body connectors that are different as well.

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What are the body connectors that you refer to? I was only aware of the CAS, IAC, power transistor, coils and TPS and all of them would be on the motor he would be transplanting from his 91 gst along with the engine and ECU, it that was the case.

buhay6 said:

And to add to the shift linkage info you will more then likely need to switch selector arms on the tran as well ast the linkage bracket depending what year the tran is. 90 cables, shifter base and selector arms are completely different from the 91-94 models......I just went through this whole ordeal.

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I was suggesting it as a quicker and cleaner swap in case he was to install a 91 transmission.

buhay6 said:

If you use the 91 engine harness in the 90 there are some body connectors that are different as well.
And to add to the shift linkage info you will more then likely need to switch selector arms on the tran as well ast the linkage bracket depending what year the tran is. 90 cables, shifter base and selector arms are completely different from the 91-94 models......I just went through this whole ordeal.

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Do you know where i can get the arms and brackets?

serviceguy said:

What are the body connectors that you refer to? I was only aware of the CAS, IAC, power transistor, coils and TPS and all of them would be on the motor he would be transplanting from his 91 gst along with the engine and ECU, it that was the case.

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They are engine-to-body harness connectors that are different. Every bit of what is different in the engine control harness is covered here: http://www.dsmtuners.com/forums/articles-electrical-wiring/412841-1990-engine-control-wiring-harness.html.

gtrej01 said:

I also have the shifter base and cables for a 91+ transmission if you want to go that route.
I'll get ya some good prices on them.

Also not sure if the car already has a 255 Walbro.

If you need any help when your putting it together let me know Ill try to help ya out.

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Ya ill probly pick those from you. just because itll probly be easier to find that trans than a 90 and if im swapping to 91 engine, harness, and ecu i might as well keep everything same year.

serviceguy said:

I would swap the ECU and harness from the 91 to the 90 (maybe lose the cruise control while you're at it or swap that one too from the 90).
If the transmission is from a 91 up I would also swap the shifter assembly and cables from the 91. Make sure you use the correct transfer case too.

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As far as swapping the harness to 91 i dont have to worry about the fact that the 91 harness is from a fwd and the 90 car is awd? Sorry if these questions sound really newb but i just dont want any suprises when i do decide on the route i end up takeing haha.

19Eclipse90 said:

They are engine-to-body harness connectors that are different. Every bit of what is different in the engine control harness is covered here: http://www.dsmtuners.com/forums/articles-electrical-wiring/412841-1990-engine-control-wiring-harness.html.

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So would it be easier to just swap harness rather than just wire in the connectors?

chris00326 said:

As far as swapping the harness to 91 i dont have to worry about the fact that the 91 harness is from a fwd and the 90 car is awd?

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Nothing to worry about here.

chris00326 said:

So would it be easier to just swap harness rather than just wire in the connectors?

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It would be easiest to retain all 1990 electronics and swap pins 6 and 14 at the ECU harness connector so that you can properly use the 1991 ECU in the 1990 car with 1990 everything else related.

But if you insist on using the 1991 electronics, I would recommend using the 1991 harness as well. As the link I provided last time details, there are those engine-to-body harness connectors that will require attention if you do swap harnesses.

19Eclipse90 said:

But if you insist on using the 1991 electronics, I would recommend using the 1991 harness as well. As the link I provided last time details, there are those engine-to-body harness connectors that will require attention if you do swap harnesses.

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Ok that was the next question. i noticed in youre article to use the 91 ecu to just swap pin 6 and 14 and it was mentioned above as well. i just wanted to see if the 90 electronics were direct replacement on the 91 motor. if so i would rather go that route cus i really dont want to swap out the haness haha.

yes the 90 electronics will swap over at the end of it a 6 bolt motor is a 6 bolt motor the harness and plugs on sensors are whats different

I was just trying to give you a little more knowledge on what's all different just in case you don't retain your 90 harness and the need more info. I had to deal with a lot of messing around on my build I'm just trying to provide you with as much the info as I can.
Like brian said it is easier to just swap pins but then your still limited to 90 electronics I some cases I just prefer to swap 91+ to avoid compatability issues.

As for the tran arms it all depends what year of tran you get/have. All shifter mechanisms like cables, bases, etc are the same between awd and fwds whether it be turbo or n/t. This is with the exception of the year differences of course. Hope I didn't cause any confusion if so let me know.

chris00326 said:

Ok that was the next question. i noticed in youre article to use the 91 ecu to just swap pin 6 and 14 and it was mentioned above as well. i just wanted to see if the 90 electronics were direct replacement on the 91 motor. if so i would rather go that route cus i really dont want to swap out the haness haha.

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Once you take a couple of these cars apart it becomes rather easy. You can swap on 90 electronics onto your 91 engine which will solve your compatability problems but your then limited to 90 only. Swaping the body harness actually isn't to bad either the harness it separates into two parts by the drivers side fuse panel.