1G Using 91 ISC in 90 TB?

[Dsm panda]

So I know 2 pins are switched (4 and 6) and the polarity is reversed but is it possible to rewire the pigtail to to be compatible? I've read that it will bolt up but work in reverse.
http://www.dsmtalk.com/forums/archive/index.php/t-223575.html

Came across this in a thread
"The ISC is a little more complex since the pins to the ECU moved around from the later connector.
B-02 to the 90 sensor pigtail is wired:

1 Blue (ECU P58)
2 Red (MPI +12 Power)
3 Yellow (ECU P59)
4 White (ECU P67)
5 Red (MPI +12 Power)
6 Black (ECU P68)

The 91+ connector B-04 plugging into the ISC is slightly different: (note 4 and 6 swapped)

1 Blue (ECU P58)
2 Red (MPI +12 Power)
3 Yellow (ECU P59)
4 Black (ECU P68)
5 Red (MPI +12 Power)
6 White (ECU P67)

The post was on throttle body swap and this was posted by steve
http://www.dsmtuners.com/threads/1990-swap-to-91-94-throttle-body.301466/

 

[mitsubishikid]

It looks like swapping the 2 pins, as mentioned above, is necessary, I've heard of the reverse polarity, these posts seemed to have good info on the topic, I planned to do this on my talon but never got around to doing it , I hope this helps out. http://www.dsmtuners.com/threads/1990-isc-motor-–-reverse-polarity-for-new-part.514056/
http://www.dsmtuners.com/threads/91-iac-in-90-looking-for-the-ecu-pinouts-between-90-91.438696/

 

[Dsm panda]

Thanks ! And i just got a 90 Laser RS with a bad ISC. After testing it idles at 2k picked it up for 1500 no rusk 80kmi. But i cant find that 90 ISC anywhere but i have a 91 TB (no FIAV) and good ISC... but it looked like no one tried it yet. its all original i wanna keep it as close to.

 

[1990TSIAWDTALON]

I made a conversion harness for my 90 so I could use a 91+ TPS. Works fine in my car, you are in the right track. I didn't want to hack my harness. I did the same thing with a ARC-2 box and converted it to a 90 plug also. ​

 

[Dsm panda]

Yeah i came across one of the conversation harnesses and it sparked the idea to just swap isc insted of tb like everyone did. My only concern is do they both have the same range of motion and is 1 step the same distance. Time for science thanks for the help ill see if it works!

It does indeed fit had a spare bad pne to see and test with. I used a micromiter to check before hand but they are within .001mm so will update once i have a good one on the car and it idles good.

 

[mitsubishikid]

I actually had to use a "90 coil pack on my mirage 4G63T swap, the harness I used was a 91-94 wire harness and it had the 91-94 triangle 3 pin coil pack connector, I swapped on a 90 4 pin coil pack connector, and then added an additional shielded wire all the way under the dash to get the mirage tachometer to work correctly it needs to see a signal like the "90 dsms have in order to work correctly.

 

[Dsm panda]

Did you use a 91 throttleboddy or 90? And ill be putting this in in about an hour so if my spedo dont work i know why so thanks f1pr that haha. Im useing the 90 tps ips and tb only thing 91 is the isc my understanding is it will just work in reverse if i dont flip the wires but if it does mess with speedo ill let you know. I made this for anyone like me who cant find that metal isc and dont wanna swap fuel rails and coils just to replace a bad isc. Hopeing to save some people head achs fingers crossed my spedo isnt affected!

So in order for a black isc tp fit you must oval out the holes and flip it 180 deg otherwise it hits the tb elbow. Once my ecu gets repaired ill let you guys know how it works. (Caps gave out on ecu this was something i knew about and is the cause of my bad isc) but all in all i dont see why it wouldnt work im staying optomistic some one has to be

 

[mitsubishikid]

I used a 91-94 Throttle-body, sensors, and fuel rail, but you only have to look out for the tachometer, if you change over to the 91-94 ignition coil pack, so your tachometer should be all good.

With my "90 Talon TSI AWD sensor upgrade to "91-"94 parts, I only ever managed to get the time to make a CAS adapter, so I basically cut a 90 CAS pigtail and added a "91-"94 pigtail and blacktop CAS, I hated how brittle the wires get on the "90 style CAS, being that they exit the CAS on the bottom, any oil leaks from the CAS seal, will more likely get on the wires, and add the extra under-hood Turbo heat, and a few heat cycles, and you have some pasta noodle brittle wires on your "90 CAS, of course this is more a problem for people that pay no heed to the upkeep of the car, but still a good mod for the "90 cars none the less.

This is why I love the "91 DSMS.
"91 pros:
still have the retro cool flip up headlights.
6 bolt motor.
"91-"94 sensors are easier to find.
The only thing you need to really do on a "91 AWD is add a 4 bolt rear. of course you could get away with 3 bolt stuff depending on what you are doing with the car.

 

[Dsm panda]

I have one of each id agree i like the 91 set up too but hey good first try guys
And yeah from you post i figured you did what i was just trying to avoid and keep mine as close as i could to original plus i wanted the cheep solution i didnt wanna source all the 91 stuff i looked into it and said o can make this work.

 

[Dsm panda]

To any one in the future trying this you can make a 91 isc work with a 90 tb you have to oval the isc holes slightly as it hits the tb elbow one way and just wont fit the otherway. You must also extend the wires and swap the black and white wires ( 91 isc works in reversed polarity from 90s).
I just wanted to update becouse to many threads never have a final update with a solution or answer and people serch and are directed to them so hope this helps!

 

[BoostedTalonTS]

Thanks ! And i just got a 90 laser rs bad isc after testing it idles at 2k picked it up for 1500 no rusk 80kmi. But i cant find that 90 isc anywhere but i have a 91 tb (no fiav) and good isc... but it looked like no one tried it yet. its all original i wanna keep it as close to.

Dang man, I'd have recommended a Classifieds WTB add if you were looking for a '90 ISC... I just gave two away with some '90 TB cores a few days ago! I'd check with Steve (stevemonroe) over at www.throttlebodys.com, he might still have them

 

[Dsm panda]

Eh i wanted to do something different as well as the fact that they will eventually all be gone and the car now has the black isc wich i understand to be a better unit. I just paid to have ecu fixed and i feel safer that the black isc wont fail and cause a repeat frying of the ecu. But i guess i should have looked a little harder oh well maybe some day this will save someones 90 tb