So I recently bought a 92 AWD Talon. I've been out of DSMs for about 5 or 6 years.
After tearing into it and trying to fix some of the minor issues, I found it has a 90 FWD Cali ECU. The car has a 6 bolt swap (Previous owner said "JDM" but it doesn't have the cyclone manifold so I can't be 100% sure). I didn't realize that before buying a ECMLink that included a 91 ECU. Put that ECU in and the car ran like crap.

If I do the pin 6 and 14 swap will I be all set for the most part? I haven't looked at the TB or other items to see if they are the 90 or transferred from the 92's engine that it had originally. I'd really like to use the 91 ECU I have and not have to find a socketed 90 ECU to work with.

I did use the search, but most of the posts I found were for people with only two of the three issues I have (EG 90 users wanting a 91+ ECU, and a 91 user wanting to save money and get a 90 ECU).
Thanks.

If it has a '90 ECU with a '91+ harness, it required pins 6 and 14 to be swapped in order to run properly.

To use a '91 ECU with a '91+ harness, the pins need to be in their original configuration.

When I had my 90 ECU I just changed two pins 6 and 14, when it went into my 91, I'm glad I was able to make that change, saved me from buying another ECU.

I'll have to look at the 90 ECU to see if they did that...but running right now without major issues its:
90 ECU and as far as I know a 92 harness, 90 engine
When I installed the 91 ECMLink ECU it flat out ran like crap (I have another post in the tuning section about that)- stalled on start up, engine was actually noisy.

I guess I need investigate more to see why the 90 ECU works.

Sounds good let us know how it goes, if the its running correctly now, you should be ok. I would start by looking at the ecu wiring, they could have done a hack job, or you may be able to see if they tinkered with those inputs on the ecu.

Perhaps I wasn't as direct before as I should have been because it sounds like there's still some question. If you're running a '90 ECU in that setup, then the pins HAVE BEEN swapped. To run the '91 ECU, the pins must be swapped back.

iugrad92turbo - yeah it runs now, but with a stock 90 fwd ecu as opposed to my 91 ecmlink ecu so i need to find out why.

19Eclipse90 - thanks. i will be checking that out tomorrow. reading up on this thread http://www.dsmtuners.com/forums/art...4-ecu-swap-into-1990-dsm-ignition-wiring.html to see what i need to look for. I never got this in depth with my previous dsms.

SoopaStar said:

http://www.dsmtuners.com/forums/articles-electrical-wiring/302812-1991-1994-ecu-swap-into-1990-dsm-ignition-wiring.html[/url] to see what i need to look for.

Click to expand...

They shouldn't have needed to do any of that. It's only an issue on a 90 car due to the gauge cluster being tightly coupled to the design of the 90 ignition. The 91+ ECU loads the signal from the coils in a way that the gauge fails.

You have two issues to investigate. What type of engine sensors, ignition, and wiring is still on that engine 90 style or 91+. Hopefully you have 91+ parts here and not the older ones.

What style of wiring pinout is on the ECU connector, 90 style or 91+.

Disconnect the IPS at the throttle body. Use your multimeter to check which pin 6 or 14 the IPS is connected to. Make an extension for one of the leads so you can reach from the engine bay to the ECU if needed.

For a 90 ECU it should be pin 6.
For a 91+ ECU it should be pin 14.

Spent about 10 minutes in the garage tonight and took a photo of the PT and coil pack plugs. Ugh..90.

A '90 harness and electronics (IMO) aren't that bad. In any case, the advice given remains the same. The car was running with a '90 ECU and now we know with a '90 harness, so to use a '91 ECU with the '90 harness, you need to swap pins 6 and 14.

I guess that's not so bad. My money is invested in a 91 ECMLink setup, so the only other option would be to get a socketed 90 EPROM ECU and swap the chip.

19Eclipse90 said:

A '90 harness and electronics (IMO) aren't that bad. In any case, the advice given remains the same. The car was running with a '90 ECU and now we know with a '90 harness, so to use a '91 ECU with the '90 harness, you need to swap pins 6 and 14.

Click to expand...

Agreed. My main issue with the 90 parts is they are largely unique and likely old. That's make maintaining them difficult.

I went ahead and ordered an ECU harness extension from Boomslang Fabrication - The Performance Wiring Specialists. They don't list it on their website and its not cheap ($179). I'm having them swap pins six and fourteen on the harness. I went this route for two reasons -

1) I can easily swap back in the stock 90 ECU if I have problems
2) I can tap into the harness outside of the car and properly solder/shrink wrap any connections I need to make without tight confines of fitting myself under the dash.

The idea of not cutting into the factory harness really appealed to me. Should have it next week.

#2 is the reason why I suggest using an adapter, just like when installing a turbo timer.

Swapping the two pins is something that is 100% reversible and takes about 30 seconds with a small jewelers screwdriver. No cutting the harness is required, that's a hack job.