Hello everyone, I'm looking for some help. I own a 1983 Subaru Brat non turbo automatic. Apparently the po installed a Nippondenso distributor at some point. According to a mechanic friend and also the shop manual it Brat's should have a Hitachi. I am having issues with it losing all spark above 2200-2500 RPM's so my mechanic friend recommended changing the coil and distributor back to factory specs. I found and purchased a rebuilt Hitachi. The question I have is that the pickup coil does not have any markings which connector is positive and which is negative. I am attaching a picture of what I am looking at. Does anyone know which is positive and which is negative? I couldn't find any info on this in the shop manual and the mechanic doesn't know either. Thanks for any help. Much appreciated. Bill

I usually go by the shape of the wiring as this is something that’s never changed in my brumby. 

Someone on here will know for sure. 

I can check it out thoroughly in a few days and report back if it’s not urgent.

Thank you sir, no hurry. The wiring was cut and spliced when the original Hitachi was replaced with the Nippendenso. Thanks again, Bill

Maybe swapped for the advance curve. That was a bit of a thing to do for some. I’m not positive that applies to yours but i seem to recall the automatics had a better advance curve and maybe FWD different from 4wd ? I would have to check a parts manual. But that was my only thought on why they swapped it out. 
 

My 79 4wd wagon was swapped out with a FWD complete engine and exhaust. So i had to decipher that at one point due to ignition parts. Same deal it’s Hitachi or ND.

Good luck with it. 

According to the shop manual all the 4wd soobs had the Hitachi in 83. I did notice the curve in the Nippondenso vacuum advance arm. It is straight on the Hitachi. I don't know what difference that would make but when mine starts dogging out and loses all spark at 2500 or so RPM, it does sound like the vacuum advance is not working properly. That was the first thing I checked but it seemed to be ok. I am hoping once I figure out this wiring the Hitachi will solve the problem.

Ignition timing advance from the weights expanding etc inside the distributor. 
 

But yes there’s also the difference of the vacuum ports. 
 

What I’m getting at is folks had appreciated that ignition curve advance from the different distributor. Wish I had that crisp memory of which and why but maybe the archives might hold some info. 
 

But just reverting to stock it won’t mean much. 
There might be wiring diagrams online. Or they’re definitely in the back of all factory service manuals. I sold off my 80s but they’re cheap enough usually. 

Went to get a pic...  but the Hitachi dist in my '83 wagon is completely different. 

I found this googling, and it has a pic that should do it: https://ausubaru.com.au/viewtopic.php?t=21289

Black with white is positive, yellow is switched / coil negative / tach /etc.

 

Edited November 9, 2025Nov 9 by bushytails

Thanks so much bushytails!  Very much appreciated!

Just posting an update in case anyone else runs into this. As I said earlier My 83 Brat had a Nippondenso distributor [Cardone 31-812]. I swapped it out with a Hitachi [Cardone 31-810]. This solved the problem with losing spark at 2-2500 RPM. Thanks to all who gave advice.