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MDC, what was the fix??
 

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Can't really tell what's going on there. What is that electrical tape harness running down the side of the ECU? Is that supposed to be the dash side harness for the Mk2? The problem I see is that you cut the black with red stripe wires in the Mk3 engine harness. That wire is the switched side of the EFI main relay. In the Mk3 that enters the harness at the C1 connector which is over by the fuse box in the Mk3 and the ECU is the end of the line. It runs thru the harness and powers a bunch of things and enters the ECU. It looks like mainly ISC, diagnostic +B, 02 sensor, and a couple of VSVs. Doing what you did effectively cut the extension cord and bypassed everything. The black with yellow should be connected to EFI fuse and black with orange runs to the coil side of the EFI main relay
 

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Discussion Starter #23
Can't really tell what's going on there. What is that electrical tape harness running down the side of the ECU? Is that supposed to be the dash side harness for the Mk2? The problem I see is that you cut the black with red stripe wires in the Mk3 engine harness. That wire is the switched side of the EFI main relay. In the Mk3 that enters the harness at the C1 connector which is over by the fuse box in the Mk3 and the ECU is the end of the line. It runs thru the harness and powers a bunch of things and enters the ECU. It looks like mainly ISC, diagnostic +B, 02 sensor, and a couple of VSVs. Doing what you did effectively cut the extension cord and bypassed everything. The black with yellow should be connected to EFI fuse and black with orange runs to the coil side of the EFI main relay


Oh wow thanks!
So the electrical tale part, thats what the shop did. There was a green wire from right side of glove compartment, assuming this may be part of the ignitor assembly but not sure how to test that theory. Other than that green wire, there are 7 other wires.
So from the mk2 harness(1984), he cut these wires.
Blue/white - speed sensor?
Black/white - this is 12v with key on
Red/yellow - when I jump power this sounds. like the efi m-rel
Black/yellow - ? Check connector?
Yellow/green - ?
Yellow/black - ? Check engine?
Green - igniter?
Blue/red - check engine indicator?
Then he made an extended harness(the electrical tape harness) he was an older dude so probably just made it easier for him to get in there. The wires cut from the mk3 harness which I think was an 89 harness at that point. I have an aem ecu I ordered from driftmotion, the engine is 87(yellow plugs).
So the wires he cut(from the 89 if I am right) where these.
Pink - speed sensor?
Black/orange - ign fuse?
Black/yellow - 12v. Battery?
Yellow/black ?
Yellow - fp/g2?
Green -?
Black/white - nsw?
Grey/Green- ?

I should have included this earlier.
4 of these wires have power when ignition is in on position. 1 of those 4 wires has only over 9 volts. The other 3 have 12v. I can jump and hear the circut opening relay, main engine relay?on passenger side wheel well in engine bay, and the other sounds like the efi m-rel.
Every place I've looked for the ecu pinout for the 24 pin Connector seems wrong, unless I'm doing it wrong. I like to think im fairly knowledgeable when it comes to wiring but no pro thats for sure. Im trying to wire it back up how he had it, or find another way to do so. I have all extra stuff out of the car, ac stuff, vacuum (some), and other things. I told him when he wired it up that I just want the engine to run and thats all, ill do the rest. So im just trying to put it back together like he had it, unfortunately he's no longer with us so I can't really ask him what he did. Ive also looked at all these 7m swap threads and everything I am following doesn't work, and things like the "u" connector I cannot figure out.
I hope this helps. I also hope this helps enough to where it may be just a simple fix lol but I don't think so.
 

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Discussion Starter #24
The ones that I cut, I was following the color code from the spliced mk3 harness to the same color on new harness and nothing worked. So I started looking at junkies old thread and some other ones. Then downloading images from Google for the pinouts. Like these..
15675
15676
15677
15678


So here's where I did it the way these diagrams look, unless I'm doing it wrong(reason why those wires were spliced)
Again hope this helps. Thanks again
 

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Like I said you need to connect where you cut the black/red wire in the engine harness. That's why you don't have any power in the engine harness. You really need to buy the EWD for the car and the engine. The schematics in the back of the TSRM are borderline useless. They don't show you any of the intermediate connectors and how things route.

So the wiring on the Mk3 harness you need to wire up that 3rd ECU connector. All the connections you need would have went to B1, M1, and C1. M1 and B1 are near the ECU and C1 is near the fuse box in the engine bay. The easy way to look at this is the X connector on the Mk2 ECU and match up the descriptions on the Mk3 "t" connector and connect them.

If you have the EWD it lists what voltage you should have on each pin. BTW which AEM ECU? Not the plug and play hopefully.
 

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Discussion Starter #26
So what i have isn't the ewd?
Ok ill do what you said. Still having troubles figuring out a few of those connectors, or what they look like rather. But I thought I was using the same diagrams that everyone else uses, you mean to tell me there's an easier way? Haha I hate to ask since there are 100s of thread on 7m swaps and sometimes it seems very simple and sometimes it also seems like a pain. So is there a better site than Cygnus and whatever else I was finding those things on? Also this is the aem ecu, please tell me this would still work. Cost me like 1500 bucks or something
15686
 

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The schematic at the back of the manual is just the basics. Basically it runs from A to B and that's about it. The EWD identifies all the connectors in the middle, where they are, has a picture of all the connectors in each section, and gives you a testing specs for many of the circuits. The EWD is like 100 pages of wiring vs the like 10 in the TSRM. The Mk3 EWD is on cygnus, not sure what year though;


I had an AEM S1 and it was a piece of crap. It died a couple of times. I would have spent the money and got the infinity. That is what I run on my 2JZ and its worlds better than the old AEMs. Not sure if they support the 7M yet though. The VE tuning is a way better method of tuning
 
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