Resolved 1990 ECU swap

[vtechaha]

I have a 90 gst-blown motor, and i just acquired a 91 gsx and i was wondering if the ecu can be swapped over since someone stole/cut the one outta the 91gsx. Thanks

 

[gr8popp]

the 90 ecu will work in the 91 but you have to switch two pins. check vfaq.com and go to ecu it says what pins need to be swapped. If I'm not mistaken you will want to switch your gauge clusters also. The tach won't work right.

 

[turb0talon92]

i was wondering if both cars were auto or manual.... only because i had a 92 Talon Tsi Fwd which was manual and i tried putting in an ecu from a 90 awd auto and it didn't work right at all.... at first it did and then it just went nuts on me and the car wouldn't start...well hopefully this is helpful...

 

[vtechaha]

yeah both manual. Thanks for the fast reply, i got the 91 awd for 50 bux-someone stole the ecu and cut alot of the wires outta it. I got a wire schematic for both years and the directions for the 6 and 14 pins and im pretty good at electrical issues, (or we'l see) you guys helped alot! its funny cause my 93 probe gt 5speed has a auto ecu in it and it has never had any issues.

 

[steve]

i had a 92 Talon Tsi Fwd which was manual and i tried putting in an ecu from a 90 awd auto and it didn't work right at all.

There is no such thing as a '90 Turbo Automatic FWD or AWD.

If I'm not mistaken you will want to switch your gauge clusters also

That's only a problem on a '90 car with a 91+ ECU.

Steve

 

[GSTBlack95]

There is no such thing as a '90 Turbo Automatic FWD or AWD.


That's only a problem on a '90 car with a 91+ ECU.

Steve

So your saying that 89-90 never came auto in turbo, fwd or awd, but 93 and 94 did? WTF

 

[gr8popp]

There is no such thing as a '90 Turbo Automatic FWD or AWD.


That's only a problem on a '90 car with a 91+ ECU.

Steve

That doesn't make sense. If I take the ecu from a 90 and put it into a 91 the tach will work, however if I switch a 91 ecu into a 90 it doesn't work

I ask because I have 90 GSX the tach does not work. I bought one from a guy on e-bay who swore the cluster came from a 90 and after installing it, it still malfunctions.

So to this. I have an EPROM from a 93 turbo automatic, I am going to send it to ECMTuning to get socketed and chipped for DSMLink. Do you think I will have any issues?

 

[steve]

So your saying that 89-90 never came auto in turbo, fwd or awd, but 93 and 94 did? WTF

The first year of turbo automatic DSM's was 1991. All 1990 model year turbo cars were 5 speeds.

Steve

 

[steve]

If I take the ecu from a 90 and put it into a 91 the tach will work, however if I switch a 91 ecu into a 90 it doen't work

That's correct. There are significant differences between the 90 cars and the later 1Gs. The '90 ECU has no problem working with the '91+ power transistor modules tach signal and the '91+ gauge but the '91+ ECUs cause problems when used with the '90 tach signal gate on the coil pack and the '90 guage. The work around is to use a '91+ PTM and wire the ECU to it leaving the gauge running off the original tach gate and stock wiring.

This isn't exactly new news. The problem has only been known about for say 14 years.

Steve