Resolved 1990 ECU Swapping ?'s

[DECODER22]

Ok I picked up a 90 Eclipse GS-T and I think ECU basically crapped out. Well I got my 90 Plymouth Laser RS turbo and I'm wondering can I swap the Laser ECU into the Eclipse to see if the ECU was the probblem? Are they compatible there both 5 speed etc?

 

[LandoAWD]

Ok I picked up a 90 Eclipse GS-T and I think ECU basically crapped out. Well I got my 90 Plymouth Laser RS turbo and I'm wondering can I swap the Laser ECU into the Eclipse to see if the ECU was the probblem? Are they compatible there both 5 speed etc?

Yes, you can swap them.

This could have also been answered by searching.

 

[DECODER22]

thank you

 

[steve]

It's possible (and likely) that they are the same part. There isn't any difference between 99% of the Chrysler branded and Mitsubishi branded vehicals. So assuming that both '90 cars are Federal spec FWD Turbos the ECU's would be identical.

Steve

 

[EcliptikIlluzio]

Is there some difference in FWD vs AWD ECU's? I have a 90 engine from a Talon AWD 5 speed that will go into a 90 Eclipse FWD 5 speed. Will the ECU swap with it or is there something special about the AWD vs FWD ECU? I thought that they were all the same provide that the only difference was the drivetrain and the years and everything else were the same.

 

[steve]

Is there some difference in FWD vs AWD ECU's?
I have a 90 engine from a Talon AWD 5 speed that will go into a 90 Eclipse FWD 5 speed.
Will the ECU swap with it or is there something special about the AWD vs FWD ECU?

Yes there are differences between the '90 AWD and FWD Turbo ECU's but they are interchangable.
The differences are in the software. The FWD version has a earlier version of the code than the AWD.
I haven't looked much at the E705A FWD code to provide specifics.

Steve

 

[DECODER22]

Well I swapped them and sure enough it was the ECU. I bought the car for 500 dollars the Eclipse GST last night of DSMTrader.

Swapped the ECU of my Plymouth just to test and it runs fine, since its a 90 Eclipse GST which ECU's can I use, so I can start searching for one? thx

 

[steve]

Here's a list of ECU Part numbers. You can use either the FWD or AWD '90 Federal ECU's. Using the later model year ECUs in a '90 requires reworking your ignition and tach along with swapping pins 6 and 14.

Steve

 

[EcliptikIlluzio]

When you say reworking do you mean switching those 2 wires in the ECU?

Not to be a pain but my 90 ECU looks funky. It has be altered because there are wires under it that has been redone. I don't like the way it looks. When I bought the AWD it ran absurdly rich and I couldn't fix it. Maybe that was why?

Steve, I have a 91 FWD ECU and the caps need to be replaced. However there is a little leakage and some slight corrosion evident but doesn't look like anything was eaten through. You think the ECU is still good if the connections haven't been eaten through? I see no burn or smoke marks either.

Lets say this ECU is fine and I fix the leaks and clean it up will I be able to run the car by simply switching those 2 neccessary wires?

 

[steve]

When you say reworking do you mean switching those 2 wires in the ECU?

No when I say reworked, I mean that in order to use a 91+ ECU on a '90 car and have the tach work right you have to switch to a '91 ignition and tach, reworking the whole ignition circuit. The two wire swap is fine if you don't care about a working tach or are putting a '90 ECU in a '91-94 car.

Not to be a pain but my 90 ECU looks funky. It has be altered because there are wires under it that has been redone. I don't like the way it looks. When I bought the AWD it ran absurdly rich and I couldn't fix it. Maybe that was why.

I hate having to blue wire parts of the ECU and try to avoid it by repairing the circuit traces but sometimes you just don't have any choice. Done correctly it shouldn't look bad and will perform as good as new.

I think I already answered the question about using the later ECU.

Steve

 

[EcliptikIlluzio]

Thanks for the help man. The AWD ECU hasn't leaked but there is some sort of rusty looking stuff on some of the soldering. It wipes right off but I didn't think that could rust. Any ideas?

 

[Whatdooin]

Thats the solider rosin its ok