New guy needs help with engine swap wiring.

[wurkenman]

Hi,
I’m Terry, and I’m new here. I am looking for some guidance. My son and I dropped a 1994 JDM GC8 engine in his 1992 Legacy. I am 99% sure that the wiring is correct. Spent a lot of time tracking wires. I know more about ECU’s than I ever cared to.
We are using the coil on plug packs that came with the engine. Did not have the correct igniter for the engine. If anyone has any ideas about where to get the correct one let me know. Right now we tried an igniter off of an SVX, just because we thought we could just omit two of the terminals. We can get the car to turn over and fire at times using some various wire combos, but so far nothing seems to work. I am out of ideas. Where could we get a set of plug wires as we need to find somewhere to mount a coil to try the original type of ignition set up. I am open to any and all ideas at this point.
Thanks any and all that might help.

Terry

[asotwavb]

Not sure how much help i can provide, but since no one has chimed in yet i'll start some discussion.

Which PCM are you using?

What is the engine code of the motor you are installing? EJ20g?

Is this a factory Non-Turbo Legacy? Or a sport sedan originally installed with a EJ22t?

For what its worth i have a EJ20G Swap in my 1992 Legacy Sport running off factory wiring, ignition and PCM.

[Legacy777]

Hi Terry,

Welcome to the BBS.

The stock ECU on the US Legacies is meant to run a wasted spark ignition. You will not be able to run the coil on plug setup with the US ECU.

There is a converter to go from 4-to-2, but I'm not aware of anything that does 2-to-4. Check out this thread as it has some good background on the ignition system and those folks that are using the overseas ECU's with COP to run the US engines.

http://bbs.legacycentral.org/viewtopic.php?f=19&t=46157

You may want to pm or email Rob and see if he has any suggestions.

As, asotwavb asked, is this a non-turbo or turbo motor you swapped into your son's Legacy?

[wtdash]

Hi,

What ECU? The stock Legacy ECU doesn't have the 2 extra wires for the 4 coils. THIS POST may help.

Guessing you used the engine harness (under the intake manifold) that came w/the JDM engine? You should be able to swap in the original Legacy harness, mount the Legacy's coil pack, and use plug wires from a DOHC EJ 2.5 engine ('96-97 OB/GT or '98 Forester/Impreza RS). Make sure you get the wires that match the female coil pack connections on the Legacy - not the newer male connections.

I don't know enough about where the IAC/ISC, TPS, etc. are on the JDM engine, but you may need to extend some of the plugs/connectors, but I think the connectors are the same.

Another option is to get the ECU for the JDM engine, buy Rob's EJ20G Adapter and it should run w/the stock igniter. The ECU's 4 plugs should be the same.

It shouldn't matter but if it's a EJ18 or EJ20, the ECU plugs may be different...but if you're using the JDM harness, not sure how it's wired???? The EJ18 in the USDM Impreza is only 3 plugs.

GL,
Td

[wurkenman]

The code on the engine is just EJ20. JDM engine. I put the JDM ecu in the car and ran the two extra wires off the stock harness for the added coil outs to the igniter. The GC8 turbo engine is replacing an EJ22 USDM engine non turbo. I did not have the correct igniter for the 4 cyl coil on plug system and tried a 6cyl from an SVX, but so far no luck. I was hoping with the 6 cyl igniter that it was just looking for a pulse to release a signal, and I left two terminals open on each side of the SVX igniter.

I have an extra coil from my 98 Outback and the wires. We are going to try and convert it to the stock coil set up from the US ignition system.

Thanks for all the help so far, you guys rock. I do belong to an Outback forum, but not much help from them in this area. I also belong to a Harley and a Diesel truck forum, but those guys aren't interested.

[Legacy777]

That's interesting that the SVX igniter didn't work. Are you sure you wired it correctly?

[wurkenman]

That's interesting that the SVX igniter didn't work. Are you sure you wired it correctly?

I sure thought I did. Probably need to go back and double check some wiring. Where can I get a set of plug wires that will fit somewhere besides on top of the intake. The JDM intake runners are higher than the stock one. I can't mount a coil right on top with a hood on the car.

[Legacy777]

Did you provide a ground to the igniter?

[wurkenman]

Did you provide a ground to the igniter?

Yes we used the stock ground from the wiring harness. We just ran the two extra wires from the ECU terminals to the igniter for coil 3 and 4. I don't work tomorrow, so I am going to go out and methodically check all the wires and connections again.

[wurkenman]

I am happy to report the beast lives!! Hard to believe it would make a difference if you have the crank and cam sensor wires crossed (sarcasm here). Might still be a couple of small issues to sort out. We need to get an exhaust temp sensor yet, and maybe a check valve for the brake booster line.

We did end up using the COP system with the SVX igniter. Thanks everyone for listening. I will try to get a pic up soon so you can see the little gem.
Terry

[Legacy777]

Awesome! Glad you got it working.