EJ swap rescue

[darkstealth16]

Hey everyone,

So, I have been slowly restoring (I guess you can call it that) an 87 RX that sat in the woods for 20 some odd years. Its in amazing shape despite that. Anyway... here is my issue. I am a good portion through an EJ22 swap into it. So far, Ive done alright. Got the adapter plate, clutch, flywheel modded, all that jazz. Motor is sitting happily in the engine bay bolted to the transmission ready to run. 

I started with a 94 Legacy 2.2, MT, FWD. I was pretty careful about pulling the harness, it was a junker car so I ripped the dash out, left the wires hooked to the engine and pulled it through into the engine bay from inside. Was a bit tricky, but, I wanted to unplug as little as possible. I thinned y harness out, getting rid of all the extras. I have, in front of me:

1: Fuel pump relay

2: Main Relay

3: Double Diode (people say this is super duper important, I accidently snipped a wire on it by mistake and not 100% sure where it goes. Currently have it connected to constant 12V+ as that was the best explanation I could find where that connects)

4: MAF

5: Ignitor

6: Both Main engine plugs

7: Back of engine plugs (that goes to o2 sensor, etc

 

I have 12V+ CONSTANT connected to the Main Relay (fat yellow wires) fuel pump relay (fat yellow wire) and yellow from Diode

I have switched 12V+ to ECU Ignition switch, Starter Switch (not in car, but switch off 12V power supply) and Small yellow wire on Fuel relay.

When the harness is plugged into the Engine harness, the main ground wire comes off the engine harness plug. I have followed a video made by Busaru on Youtube showing a harness test, where he grounds said harness ground wire to power supply ground, and is able to get relays to function. 

I do not have any of the gauge wires hooked up, as they should be unneeded for Fuel/Main relay to function (as demonstrated in said video I just mentioned, he bench tests his harnesses using test mode cables on ECU switched power, constant power and Ground to get Fuel pump/main/fan relays to function)

Just from this small writing, am I missing anything particularly obvious? I am about to go back outside to try hooking the harness back up to the car to see if now that I have triple checked my 12V power connections, if the issue is I missed a grounding wire or something... but, I am at a loss. Ive been struggling with this portion of things for about 2 months now (off and on of course, among all the other projects) and this is where I am hung up. The rest, hopefully will be a piece of cake, once I get past this hurdle. I will also say, this ECU did come from a running car. It ran before I took it apart. That is NOT to say that, even though I do not BELIEVE that I damaged the ECU inadvertently, but it definitely is within the realm of possibility also. I can't figure out a way to test the ECU itself to see if I can apply voltage directly to it to read voltage elsewhere... I am just not sure how I might go about testing that exactly. Anyway, I hope I have been thorough enough in this, I have searched high and low for the answers I seek... I have the FSM for the car, pin outs, you name it. At this point, I just think I have exhausted all my options of this on my own, and finally reaching out for help! I'm hoping someone will be able to lend me a hand, I would really, REALLY appreciate it!!!

Allan

 

[Step-a-toe]

I know zip but like your style.

BuMp !

[darkstealth16]

@Step-a-toe Thanks! Haha,

Well, small update. Actually, big update! Got the ECU working! Whipped out my test power supply, did some more fiddling, and isolated the grounds I need to get the ECU going. On my ottoman, in the living room, I was able to get 12V to the ECU, and with the test mode connectors hooked up, My main relay fired! Put 12v to my "switched" 12V annnnnddd FUEL PUMP RELAY is firing. Yay! FINALLY. I still have the SMJ in place. I think it was a combination of a loose connection in the SMJ, and I ran my "Power supply" ground coming to the ECU directly to the power supply source ground I am using, and got it working. So now I know, Ive got a ground off that Ive gotta fiddle with. But, the rest of my harness should be sound! I am hoping to have this thing running soon!

 

[el_freddo]

@darkstealth16 - wiring is always a hard one to diagnose over the forum, even over the phone at times! 

Glad to hear you go it sorted, it’s the best feeling short of firing up the engine with your cut down loom! 

SMJ? Super module junction or what ever that big joint with the bolt is called? If so, you don’t need that! 

Have you labelled all your wires so you know what’s what the next time you test or go for the install? 

Cheers 

Bennie

[darkstealth16]

@el_freddo - I kept the SMJ so I wouldnt have to go through and connect all the wires running through it to one another. Seemed the easiest way to go, its a solid connection, uses factory wire colors etc, and makes things pretty easy to trace. I de-pinned the extra wires coming from it, tightened it good and snug. As a matter of fact, I took it out  just a bit ago, hooked up the ECU and harness, run my 12V hot lines where they need to go, relays kicked on as they should, sprayed some starting fluid in the intake and BINGO! She ran! Sounded rowdy as all get out because it has no exhaust, and only ran long enough to burn the starting fluid (I hadnt connected fuel pump yet) but, you are exactly right! SHE RAN! And yes, all wires are labeled where they need to go etc. Thats why it was killing me I wasnt getting power and nothing seemed to be working. I went over and over it and it didnt make sense. Checked my SMJ and while it had connection, it was a bit off so it wasnt getting good contact. Tightened it down good and snug and got it sorted out. I knew trying to ask for help with the wiring would be rough, but, I was at my whits end. Thanks for the Feedback Bennie!

Allan