1G swaping a 91 4G63 engine into a 90 chassis = wiring problems?

[DSM_NOOBIE]

I purchased a 91 engine and have a 90 chassis and just read somewhere that the 90 ecu/wiring harness is different from the 91-94 ecu's due the coil pack system. i need to know what i need done to make sure the engine i have will run properly once it is ready to be installed. thanks

 

[JaxTalonTSi]

Just make sure you swap all of your 91 coil pack, power transistor, and throttle body onto the 90 engine. The oil filter housing is slightly different as well, so you may need to swap that if it is still on the engine. Then you should be good to go.

 

[nightspeed87]

so your using a 91 motor with your 90s harness. Well yea pretty much what the other guy said, but what tranny are you using? Because the 90s tranny has different shifter mounts and shifter cabels. If you keep your 90s tranny your ok, if your using a 91-94 tranny then you will need to use your shifter mount from your 90s to work , I crossed this same problem, because I have a 93 and I am building up and putting a 90s 6bolt gst engine in my car..

http://vfaq.com/mods/shifter-diffs.html

And JaxTalonTSI

Just make sure you swap all of your 91 coil pack, power transistor, and throttle body onto the 90 engine. The oil filter housing is slightly different as well, so you may need to swap that if it is still on the engine. Then you should be good to go.

Other wise everything jaxtalontsi said sounds correct, but
Can someone tell me what is different from the throttle body on the 90s supposably?

 

[Rex2342]

If your dropping a 91 engine into a 90 chassis you should use the 90 coil pack, translator, and TB since the ECU and harness are already setup for the 90 stuff. You could do the convertion but if you have the 90 stuff and it's in good shape why not just use it. The oil filter housings are also different on 90s because they use an external oil cooler where as the 91's are water cooled. Again I would stick with the 90 setup. I believe the thermostat housings and CAS are also different from 90-91.

 

[DSM_NOOBIE]

I just found out i bought a 90 motor instead of the 91....The bill of sales reads 91 but i had to make sure so i bought a carfax and ran the vin to find out its a 90. so im good to go thanks everyone