ECU HELP

[93.20G.5sp]

I have a 1993 Legacy Touring Wagon, originally 2.2t with a 4eat. It was swapped to an 02/03 wrx 5 speed, then later on converted to an EJ20G from a 94 JDM WRX. It supposedly has a Rob Tunes 95 STI ECU, but the numbers match a 94 sedan (says S instead of WRX in the thread I read) of some sort that had the EJ20G. It has the GD WRX coil conversion, but the trigger wires are wired to terminals 17-20 on the 26 Pin connector for this ECU. I've searched everywhere and can't find trigger wires wired to those terminals on any ECU, and definitely not for my ECU.

It runs smooth (up to boost and up to about 15% or 20% throttle which causes it to cut out) which makes me believe it is wired correctly because it wouldn't run on all 4 cylinders if these were incorrectly wired. Does anyone have any ideas as to how this ECU is wired or seen anything like it before? There's several wires cut and merged so I want to make sure I understand what was done. Any help is greatly appreciated, and if this is a long ramble which makes no sense...My apologies haha.

Pictures attached are of ECU identifiers and 26 pin connector that's in question.






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[ride_child]

have you looked up the stock pin out for our ecu's? id then cross reference that with the rob tune/20g ecu installation thread and you should be able to determine what is going on, or if its different, then how to fix it. you should be able to find both of those in the stickies!

[93.20G.5sp]

have you looked up the stock pin out for our ecu's? id then cross reference that with the rob tune/20g ecu installation thread and you should be able to determine what is going on, or if its different, then how to fix it. you should be able to find both of those in the stickies!

I have looked at the pin outs, that's why I'm so confused. What is done here is different than anything I've been able to find, and what's more confusing is it was turbo stock! It should've been bolt in!


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[ride_child]

no the 20g engine was a coil on plug setup and is wired so at the ecu. the 22t is a wasted spark setup and is wired so at the ecu. in order to run the 20g ecu in our cars, we either have to convert to a coil on plug setup, which is the way the original modifier went since you have a 20g engine as well.
the other route is if you are still running a 22t in which case there are a few ways you can make an adapter to trick the ecu into thinking its running a coil on plug setup, but that doesnt matter for you since you have a 20g engine.
even though you have a 20g ecu and a 20g engine, unless the original modifier did a harness swap as well, you will still have to do some modifying on the stock 22t harness.

[93.20G.5sp]

no the 20g engine was a coil on plug setup and is wired so at the ecu. the 22t is a wasted spark setup and is wired so at the ecu. in order to run the 20g ecu in our cars, we either have to convert to a coil on plug setup, which is the way the original modifier went since you have a 20g engine as well.
the other route is if you are still running a 22t in which case there are a few ways you can make an adapter to trick the ecu into thinking its running a coil on plug setup, but that doesnt matter for you since you have a 20g engine.
even though you have a 20g ecu and a 20g engine, unless the original modifier did a harness swap as well, you will still have to do some modifying on the stock 22t harness.

Ok...This post has a lot of information, that either has been noted already, or is useless. I know it was converted to GD WRX coils, I know the ECU is wired like it's a 4 channel...because that's what it is. My question is if anyone has seen this before, if so where, and if anyone knows why they would move the wires to the terminals they did when the ECU is supposedly 4 channel stock. They would normally be wired to 7-10 I believe, but they have been moved.


*Edit to explain further*
After reading again, you were just arguing my point about saying it should have been bolt in. What I meant was the wiring should have needed a lot less hacking than what was done, I've fixed and figured out 90% of it, this is the only part I don't understand.


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[ride_child]

haha ok, good luck with figuring it out.

[Legacy777]

What I meant was the wiring should have needed a lot less hacking than what was done, I've fixed and figured out 90% of it, this is the only part I don't understand.


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What Kris has tried to explain and what you seem to understand is that the wiring should not have been wired the way it was, and unfortunately only the installer would truly know why it was done that way.

My recommendation would be to redo the wiring the correct way (even if that means adding new wiring from the ECU). That way you won't be chasing wiring gremlins you are unable to troubleshoot and fix.

[93.20G.5sp]

What I meant was the wiring should have needed a lot less hacking than what was done, I've fixed and figured out 90% of it, this is the only part I don't understand.


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What Kris has tried to explain and what you seem to understand is that the wiring should not have been wired the way it was, and unfortunately only the installer would truly know why it was done that way.

My recommendation would be to redo the wiring the correct way (even if that means adding new wiring from the ECU). That way you won't be chasing wiring gremlins you are unable to troubleshoot and fix.

Kris, let's be friends. We really understand each other. lol I didn't mean to sound like a dick I was extremely frustrated with the state of disrepair the car is in.

But yes, I guess I will have to rip the dash apart and start chasing wiring. Once that's done I can figure out what was moved to where and why. If everything is hunky dory and just moved around for some reason I'll probably just leave it as moving things to the correct place will likely cause more problems. The ECU would need to be adjusted to know what terminals are what inputs and outputs correct? It runs well now aside from the vacuum leak, so once I understand how it works I'll probably just put it back together.


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[Legacy777]

So does it run ok now or does it cut out when you give it more than 15-20% throttle as mentioned in your original post?

Do you have wiring diagrams for the car? If not, check out the stuff you need to know forum for links to the factory manuals on my server.

[93.20G.5sp]

So does it run ok now or does it cut out when you give it more than 15-20% throttle as mentioned in your original post?

Do you have wiring diagrams for the car? If not, check out the stuff you need to know forum for links to the factory manuals on my server.

It cuts out still, I was inquiring about the wiring more for my own knowledge and to change a wiring diagram to show exactly how the car is wired. That way I I'm ever feeling lazy I can just take it to a shop and if it's an electrical issue they have correct diagrams.

I'm pretty sure my cutout is vacuum related as the only code is 45. I've done quite a bit of research and nothing I've found in previous threads has come up with anything good. For the cutout should I start another thread? I don't think it belongs in this section.


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[Legacy777]

What I would suggest is start another thread with that specific issue and provide a link to this thread so people can see the history.