I'm posting this for a friend I have a few states away who is working on his '84 GS.

"Ok so I have an '84 GS. I am starting to gut out the interior and I stumbled upon something. As i was ripping out the carpet in the passenger side i found this tin plate that's sloped up, so I undid the bolts and pulled it back. Is that my computer in there? It looks like it and its big and all the wires in the car run to it. If it is, then behind the drivers seat there is a little box that says Clarion. Are those the cars stereo amps? Now the biggest thing that puzzled me is the computer (if that's what it is) in the passenger side has a huge MITSUBISHI sign on it. I have also noticed that my alternator is Mitsu and so is one of my caps on the engine. Is that supposed to be right? I am swapping an 87 13b into it this weekend and I was wondering if I am gonna need the computer for that motor too? I am getting the flywheel to balance it but will I need the wiring harness too? Any help would be good help. Thanks."

So yeah, if anyone could post some responses to that, I would appreciate the help.

 

The computer is your intierior light comp. Yes the clarion box is an amp.

 

The thing under the carpet is the emissions computer, although it does run other things also. It was built by mitsubishi electronics along with the alternator and damn near every other electronic part on the car. Mitsubishi electronics corp is HUGE.

 

Id recommend the wiring harness as well. you could also do a search for the ecu pinout/cut list. hth.

 

Wahhh?? Intierior light comp? Yes it's the emission's control unit (ECU). It's easy to get it and its wiring harness, for the rats nest, out. You'll just need to find a plug for the hole--I still haven't found one that's big enough.

 

That ECU box runs a lot more than just your interior lights!

On the SE's, it also controls the air/fuel ratio via fuel injection mapping, all of the barometric controls, the ignition and tachometer signal, and most of the other electrically related parts in the car.

Your buddy is going to need to keep that in place if he wants his new engine to run. FYI,

 

Ok this is that guys friend who he is asking for. Will i NEED the wiring harness for the car or can i just use the one i alrady have??? I just want the car to run for right now. Then once i am done with that i will work on the other stuff. But thats my main goal for right now.

 

Good to see you join.

 

Ok, lets get some facts straight first...

You have an 84 GS. No fuel injection computer or anything like that. What you have is worthless to the new motor if I remember right.

If youre installing an 87 13B, it should be fuel injected, meaning you need the computer to run the fuel injection, as well as the engine harness to go from the engine to the engines computer.

The best way to do your swap IN MY OPINION, is to junk whats under the carpet now, and everything attached to it. Set the new computer for the 87 engine in in its place and run the new harness to the engine. Hook it all up and be done.

~T.J.

 

BUT, you'll want to keep the original parts in case you decide to install a model-specific 12a in the future.

Don't start throwing stuff away just because you don't need it right now - there may be someone out there willing to pay dearly for a stock wiring harness that they fried installing their new stereo incorrectly.

I have made that mistake many times, and have come to realize that the small amount of space that it takes to keep that stuff ALWAYS pays off.

Good luck on your project,

 

man i gotta say you all just ****** rock you know that. you alll give great advice. lol. i love this site. well ill keep ya posted on the swap. thanks guys