Resolved 92 ECU in 90 Talon

[Malrun]

Found out about an hour ago the ECU in my car is a MD193299. The ECU has a ECMLink V3.

I found this by digging into why ECMLink isn't connecting. It's not a 90. And that's a different problem.

Earlier in my time on the forum, I posted my tach wasn't working and I never found the fix for it. I just moved on. After finding the ECU was not a 90, I started digging and found posts that the ECU pins 6 and 14 need to be changed. I checked and they were changed. Ok then. I saw this thread a little while after.

https://www.dsmtuners.com/threads/1991-1994-ecu-swap-into-a-1990-dsm-ignition-wiring.302812/

The Power TR Unit is still a 6 pin (90). I just want to confirm that the thread I listed above is the correct path to resolving the issue for the tach not working. And to add, is this a reason why the car won't run correctly? Turns over and spits like it wants to start. If it does, sounds like it's on 2 cylinders.

 

[19Eclipse90]

That ECU part number was from a ‘93 model year AWD car with manual transmission. By swapping the wires at ECU pins 6 and 14, the ECU should be compatible with the 1990 electronics to start and drive the car.

The tachometer is a separate issue. In and of itself, an inoperable tachometer will not cause the car not to start. You state that you have the 6-pin power transistor unit. Do you also have a 4-pin coil pack? Do you have a noise filter mounted to the intake manifold or intake manifold stay? Is your gauge cluster a 1990 version (do the speedometer values end in 5’s)?

As a no-start, I would recommend running through this thread to narrow down what isn’t there to allow the motor to start: How to Diagnose a No-Start

 

[Malrun]

That ECU part number was from a ‘93 model year AWD car with manual transmission. By swapping the wires at ECU pins 6 and 14, the ECU should be compatible with the 1990 electronics to start and drive the car.

The tachometer is a separate issue. In and of itself, an inoperable tachometer will not cause the car not to start. You state that you have the 6-pin power transistor unit. Do you also have a 4-pin coil pack? Do you have a noise filter mounted to the intake manifold or intake manifold stay? Is your gauge cluster a 1990 version (do the speedometer values end in 5’s)?

As a no-start, I would recommend running through this thread to narrow down what isn’t there to allow the motor to start: How to Diagnose a No-Start

ECU pins 6 and 14, the ECU should be compatible with the 1990 electronics to start and drive the car.

Good to hear, that's all I needed to know on that part.

The car is a 4pin coil pack.
Cluster is a 90.

2 connectors are unplugged behind the manifold.
The big one had a Black/Green and a Blue/yellow wire to it.
The smaller one that looks like it goes to the filter has 3 white wires going to it. I used a bore scope to locate a noise filter and nothing there. I'm 90% sure the small plug is the filter after looking at pictures on the forum.

I appreciate your response. I'm chasing down and trouble shooting on a car I never worked on before. DSM's are new to me. But trouble shooting on this car leads you down a rabbit hole.

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[19Eclipse90]

Yep, the smaller one is for the noise filter. Without the noise filter, your tach will not function. Again, separate issue from a no-start.

These are some different versions of the noise filter. It was originally mounted to the intake manifold stay (bracket supporting the intake manifold, attaching to the block).

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The other plug is for the EGR temperature sensor on vehicles with California emissions. It is an open connector on vehicles with federal emissions.

 

[Malrun]

Thank you for your help. I think I found the reason for no start up and made a separate post on what I just found: 1G Found a kill switch linked to MPI. It's the cause of my issues?

I was confused on the write up I posted with a non 90 ecu in a 90 car. It made it look like I had to go through these steps.