90 engine & ecu swap into 92 shell

[brtmsx]

I recently purchased a 92 talon TSi AWD shell and was curious at what (if any) problems i would run into swapping my 90 engine and ecu into the 92 shell. (using the 92 harness)

And before the flaming starts, i have searched and the only thing ive come up with is swapping pins 6 and 14, and changing a couple of the connectors, for example the 90 cas, throtte body and a few others.

I was curious if there was a write up somewhere for this or if someone could enlighten me on what the "few others" were.

I also still have the 90 wiring harness, so could i just use it and save myself the trouble of having to a bunch of rewiring?

Thanks in advance guys.

 

[BrokenTsi]

If there is a harness, you already answered your own question. Switch the pins in the ecu harness, and thats done. Use a 92 CAS and ignition coil, throttle body, and everything else bolts in.

As far as transmission goes, use 92 cables, shifter base, and the bracket on the transmission. Then you can use whatever year transmission you want.

 

[brtmsx]

ok thanks.

but lets say im doing this on a budget and i cant get the 92 cas, coil and throttle body right now.

would i then be better off just using the 90 harness?

 

[nuclearr]

Its a pita to change the harness. But it would be the cheaper route monitary wise. I say its a pain, the only way I have been able to do it was to remove the dash and HVAC unit. Some one else might have figued out an easier route.

 

[skatershawn]

Actually.... i had a little trouble swappin out my harness but it wasnt a pita.... it actually took me about 30mins to remove the old AND snake in the new!!

I WISH i would have documented it and wrote up a tech thread on it for those who want to do it if fast without taking apart the whole dash!!!

 

[steve]

Lets say im doing this on a budget and i cant get the 92 cas, coil and throttle body right now.

would i then be better off just using the 90 harness?

You run a much higher risk of the car not running when your done.
You also run the long term risk of it dieing on you and not being able to find good parts.

There was a good reason that the factory changed all that stuff in the second year.

 

[Boost_Addict_88]

Its actually not that hard to remove the dash. Really the only thing is all the little screws and such (use plastic baggies and label all the screws for easy reinstallation). There's screws (6 I believe) holding the wiring in place. There's a few that you kind of have to work the dash out (if that makes sense) to get to, but other then that its not hard. Also, remove the steering wheel (make sure to put the wheels/steering wheel straight to prevent poor alignment). If you're not familiar with it, don't worry about any wires. Just grab tight and pull hard. If you have trouble, take a mallet and tap the back of the wheel on both sides to loosen it. The reason I say don't worry about wires is because 1G steering wheels are magnetic. Good luck with your project and keep us updated! ^_^

 

[ryan90]

If there is a harness, you already answered your own question. Switch the pins in the ecu harness, and thats done. Use a 92 CAS and ignition coil, throttle body, and everything else bolts in.

As far as transmission goes, use 92 cables, shifter base, and the bracket on the transmission. Then you can use whatever year transmission you want.

+1 on this.

 

[brtmsx]

I think I'm just gonna try swapping the harness for now, the car everything came out of was still running when i pulled it all so hopefully its all good.

but this is only a temporary solution, ill soon have my hands on a 92 ecu, cas, coil and throttle body soooo yeah, thanks for the input guys.

btw, i wouldn't be in such a hurry about it but the car kinda is my daily driver... haha

 

[steve]

You can still use the 90 ECU if it's in good shape. Like you said in the first post, you just have to pop pins 6 and 14 out of the connector and swap them while using the 90 ECU in a 91+ car or harness. Takes me about 30 seconds.

So what your really looking for is a 91+ turbo throttle body with TPS, IPS, and ISC, a 91+ fuel rail, 91+ CAS, 91+ coil and power transistor. If you have a good harness in the car I still think your asking for trouble. Going that route raises the risks of getting a good running car at least an order of magnitude. That would be a big deal if it was my DD.

I hope it goes well for you. We'll be here if it doesn't.

 

[2soon2]

Harness would be easiest i say. I am in the middle of doing it right now and its not that bad.

 

[steve]

Harness would be easiest i say. I am in the middle of doing it right now and its not that bad.

Not that it matters at this point but I can't believe you just said that swapping the harness is easier than changing the CAS, TB, fuel rail, coil and transistor.

What are we talking about here. Three bolts for the CAS, three more for the TB (since you just did two of them for the CAS), seven for the rail (including the four little bolts for the fuel fittings), I think three for the coil, and another two for the PTM. All of this can be done before you put the engine in where it might take 20 mins.

I'd like to see someone swap the wiring harness in 20 mins.

 

[BrokenTsi]

Why would you need a 91 fuel rail? Last time I checked, they were all the same.

 

[steve]

Why would you need a 91 fuel rail? Last time I checked, they were all the same.

Last time I checked the 91+ fuel rail is a little shorter to clear the larger TPS used on the later throttlebody.

 

[skatershawn]

I'd like to see someone swap the wiring harness in 20 mins.

well i can say i did it in 20 mins but it was like 35-40!!
the old one was cut in have and took both ends out... EASY... taped up the end that goes to the ECU and tired a rope to it and taped the rope for better measures and feed it though at the same time as i was pulling it with the rope!! it was quite easy...
i learned that trick from cabling buildings with voice and data cable for two years!

Last time I checked the 91+ fuel rail is a little shorter to clear the larger TPS used on the later throttlebody.

and NOT saying your wrong... but i didnt replace my fuel rail when i switched my TB to a 92!
:/
so i dont' know!

 

[BrokenTsi]

Last time I checked the 91+ fuel rail is a little shorter to clear the larger TPS used on the later throttlebody.

Hmmm. Didnt know that. Ive had my fair share of 90's, 91's, and fuel rails, and Ive never ran into that problem. Guess I just got lucky.

 

[brtmsx]

Ok so i got the harness swapped (easy or not) but the only issue ive ran into is the large white plug that connects to the dash harness.

The 90 engine harness plug is slightly smaller than the 92 but all the colors on the wires match up (a couple are in different locations)

so basically my question was can i just swap the plug on the 90 harness for the plug on the 92 (and just match the colors to the corresponding locations), or is the wiring different despite the matching colors, or do i have to swap the dash harness too?

but honestly either way im glad i pulled the engine harness from the 92, its hacked up... really not pretty at all.

Anyway, any help would be greatly appreciated. thanks!

 

[BrokenTsi]

Have you figured this out yet? What did you end up doing?

 

[brtmsx]

Have you figured this out yet? What did you end up doing?

De-pinned the connector and swapped them. Car runs great thus far.