I've got the coil pack upgrades and the ignitor chip bypass connector from Performance VH but I'm having some trouble figuring out what wires go where. Can anyone help me out?

Here's what I know-

New coil pinouts:
1- ECU Ground
2- Engine Block Ground
3- 12v + (Switched)
4- Signal from ECU

Now, I'm guessing that each one of those corresponds to one of the 4 wires on the ignitor chip bypass plug? But there's also that one single Black with yellow stripe wire which finds its way into the old coil sub-harness (the one that can be used to check timing).

It'd be easy enough to just find 3 out of 4 (maybe all of them but I'd hate to just guess) of those in other places and tie them in, but I have to believe that they should tie into where the ignitor chip used to be. Anyone have some insight? I've been trying to figure this out almost a week now with no luck and progress has stalled until I can get it figured out.

Thanks!

Did you buy a new subharness from VH?
The 4 wires on the output of the old 'ignitor' went one to each coil pack as the trigger.

With the ignitor bypass (new 4-pin coils) the signal from the ECU directly feeds the trigger pin on the new VAG coils. So you only use the 4 wires from the 5-pin connector coming from the ECU (the bypass harness).

Perhaps this diagram will help?

I got the sub-harness construction kit, basically just the plug that goes onto each coil along with about 2' of wire coming off of each one, so 8 pig tails. So I have the 4 wires coming off of the coil packs (White, Green, Brown, Black and a pretty good idea of what each is supposed to go to), but then I have the end of the ignitor chip bypass that those wires should go to, I just don't know which coil wire goes to which "ECU-side" (ignitor bypass) wire.

What you said does help clear up some things though! I cant see the image for whatever reason because I'm at work and it won't load.

I suppose if I know now that each of those wires that used to run to the ignitor is supposed to be routed to each cylinder on that side, then it should just come down to me figuring out which wire on the ECU-side (where the ignitor bypass is at now) goes to what cylinder on the coil sub-harness. The ground and the switched power should be easy enough to find anywhere else I guess?

So, I'll take a look at the image you attached when I get home and see if I can get the info out of it that I'm looking for. Thanks a lot for the reply!

Okay, yeah that diagram is really helpful! There's just a couple more things I'd like to get cleared up before I start chopping wires.

1) The BR/Y wire that turns into B/Y at the stock coil sub-harness, is that what I'm going to use for my switched 12v power on the new harness? It looks like that goes to the ignition coil relay from what I've read, I just want to make sure.

2) Engine ground and ECU ground. The new coils have a pin for each. The engine ground is easy, I can just bolt it to the engine where the stock ones were grounded to. But what about the ECU ground? Can that just ground there too or what do I look for in a good ECU ground?

tbs1775 wrote: ↑

Sun Jul 08, 2018 9:09 am

Okay, yeah that diagram is really helpful! There's just a couple more things I'd like to get cleared up before I start chopping wires.

1) The BR/Y wire that turns into B/Y at the stock coil sub-harness, is that what I'm going to use for my switched 12v power on the new harness? It looks like that goes to the ignition coil relay from what I've read, I just want to make sure.

1) Yes.

tbs1775 wrote: ↑

Sun Jul 08, 2018 9:09 am

Okay, yeah that diagram is really helpful! There's just a couple more things I'd like to get cleared up before I start chopping wires.

2) Engine ground and ECU ground. The new coils have a pin for each. The engine ground is easy, I can just bolt it to the engine where the stock ones were grounded to. But what about the ECU ground? Can that just ground there too or what do I look for in a good ECU ground?

2) Not as sure. What I do know is that by design the ECU chassis and engine ground are at the same potential. The ECU may also have a separate signal ground, although that signal ground is likely tied to the ECU chassis inside the box. So you could look for an ECU signal ground pin and chop into that with your 8 ECU grounds. Or, if you prefer not to chop that, you could run a 10 ga ground wire (overkill for sure!) from the ECU chassis (stick it between mounting bolt and the case) to the same engine block ground you are using for the coils.

Please post back in this forum with your completed subharnesses (pictures would be great!). I'm sure this is going to come up a few times again in the future, since it appears to be a much more modern and practical design than the almost 30 year old stock set up.

Awesome, I will be posting my results and I appreciate the help. I'll probably get started on it tomorrow before work, go buy whatever wiring things I need, and then hopefully it wont take me long to finish.

Another issue right now is that 3 of the coils won't clear the turbo manifold on the passenger side during installation without chopping the last inch off the metal cover that they come with (in order to expose the flexible, rubber, stock-like portion). The stock coil tube is pretty flexible so I was able to get them in and out even with the clearance issue of the turbo manifold. The new ones have a metal case that runs the length of the coil tube and will not bend to fit past the manifold that goes over part of the valve cover. The metal tube seems to be also have connectivity with the engine ground pin so that gives something of a clue to their purpose. I've been trying to figure out if cutting an inch of metal case off the bottom of a coil tube will effect anything but I haven't found any information on that yet. I might just go ahead and do it and see what happens. Worst case I'll just have to bite the bullet, get a couple replacement coils, and pull the motor so I can take the manifolds off.

Images:
Stock vs Coil upgrade - https://imgur.com/a/VBKpMSi
Clearance issue - https://imgur.com/a/RLYaMhF

Attempted starting video: https://www.youtube.com/watch?v=5JHCFYIaCVk
Subharness Picture: https://imgur.com/a/irpETwh

Okay so here's an update. I got them all wired, installed, and the car does turn on. It won't stay on for long and it dies. Tried giving it some gas but I can tell it just wants to die, poor car... Also my Nistune wont connect anymore while the car is running, it detects some kind of corruption on the data line. Here's how I have it wired:

Coil Pin 1 (ECU Ground) - Pin 30 (B/Y wire) on the ECU, spliced it into that, labeled as "Sensor Ground" on some pics I found online.

Coil Pin 2 (Engine Block Ground) - Bolted to the back of the engine block, stock location.

Coil Pin 3 (12v+ Switched) - Tied into the stock power supply for the coils, the 1 B/Y wire that's on both sides.

Coil Pin 4 (Signal from ECU) - Paired these up with their respective places. All the coil-side wires are brown. So in this "table" below, Cyl 1 would go Brown at the coil, then hook into the ignitor bypass (B), then turn into the stock harness color (B/R). So it kind of reads backwards and starts on the ECU-side color.

Cylinder - Color on the stock harness side - Color on the ignitor chip bypass side
Cyl 1 - B/R -> B
Cyl 3 - G -> Y
Cyl 5 - G/OR -> G
Cyl 7 - L -> R

Cyl 2 - Y/R -> B
Cyl 4 - G/R -> Y
Cyl 6 - G/B -> G
Cyl 8 - Y -> R

I *may* try to see if another ground will work for the ECU Ground wire, I have a feeling that's what is corrupting my Nistune cable. Just not sure where else I can put it. After it died the first time I pulled the trouble codes from Nistune and (besides the normal no catalytic converter code) there was Code 13 "DRC Temp" but honestly that might have been there before and I never noticed. I reset the codes and started it up a couple more times and it didn't come back.


Any ideas?

Okay it works! I got an email from Eric at Performance VH confirming that the ECU ground on the coil pack upgrades should be grounded to the block. I went ahead and made the change and it started right up. It's got some idle issues right now but I'm not currently going to attribute that to the new coils, I'll see if I can just turn the idle target up a bit in Nistune. After Windows updates finish on my laptop I'll take it out for a drive and see how it goes!

As an added note, there seems to be some extra engine noise happening. Not sure what it is yet, best case it's just lifters ticking, worst case it's knocking. Either way I'll be out to test it later today or tomorrow morning. I figure if it's lifters ticking, no big deal. If it's knocking at idle, well it's probably trash already... might as well see if the new coils fixed my hesitation problems under load. I'll double check my firing order just to be sure, but with how smooth it's idling I doubt that is off. I think if the order was jacked up it wouldn't idle hardly at all or it would sound completely F'ed up.

Stay tuned.

Update: It drives great, aside from a vacuum leak that I just found and needing some tuning. There's still some hesitation as mentioned in my other thread, not nearly as bad, not even close. I think that's a mix of the wastegates opening too low in the boost area (I need a boost controller), not opening smoothly maybe, and not having a decent tune. The mysterious sounds went away, and the idle smoothed out with a little adjustment of the throttle cable, it was probably just from a lack of oil in the upper part of the motor and needed to get warmed up after sitting around.

Problems have been resolved... for now!

Excellent news!
I had another reply to you about the ticking, but it hung up and got deleted. Short form was that HLA tick is pretty common on these motors when cold, usually goes away at full operating temp.

Yeah, I've noticed a usual amount of ticking but I wasn't sure if this just sounded like a heavier tick or if it was all in my head. I did take a short video, if you're interested in hearing it - https://youtu.be/u_RpgCQabOwa

I'll probably go ahead and get ahold of Wes to get the pre-tuned ECU from him, try and eliminate the tune/ECU as another problem. Eventually she'll be fully boosting without a problem! I have a new MAF that I'll probably put in tomorrow and see if it even works. The new one was from Ebay so who knows if it's real or just made of legos and wires. Hopefully I got a legit seller.

If the tune and MAF doesn't have it running like a top, I don't know what I'll do. I've changed almost everything else already with the sole exception of the injectors. I could go and have them cleaned for good measure maybe.