Extreme misfire after R35 coil upgrade, then back to stock

[SM514]

Please hear me out:

I ordered an R35 coil and bracket kit along with a custom harness. I'd like to keep the companies nameless for now (coils and bracket kit was separate from the custom coil harness).

I installed the kit following the instructions to the last letter. When I tried to start it, there was no spark. A little searching and found a simple mistake. The custom harness had the three wire plug with the power and ground wires switched. I flipped them and I then had spark. HOWEVER it ran like garbage. Hesitated to start, idle was rough, and it died as soon as I applied any but of the clutch. It acted as if it were rich. The brand new plugs were fouled. I added a picture of one of the. That is with less than 3 minutes of running.

 

I contacted the company and they sent me a replacement harness but it still ran like garbage.

I then checked that I had proper connection with the plugs and new coils. The spring in the custom stalks were the correct length and as the plug was pushed in, the spring moved. The resistors are also in place and making contact. Both of the other connectors were secure along with the ground. Even replaced the R35 coils with another set of brand new ones.

 

I pulled the kit and put the OEM ignition back in. It started up no problem. But it wasn't until tonight that I tried to drive it. It now acts the same as it did with the R35 coil kit. I couldn't even drive it out of the garage without it falling flat on its face. Smokes like it's rich, new plugs again fouled and now won't start. It spits and sputters but dies right away.

 

When I started this whole thing, it was fine! No problems. It has been on 2 long trips with in the past 2 months. I only went this route as the clips were brittle and decided to upgrade.

 

I do not understand what happened!

Ignition timing was not changed either. I also switched out an known good ignitor and still no change.

 

Is there a chance the power/ground wires switched in that harness messed with the ecu?

 

Help! I'm pissed!

[Dose Pipe Sutututu]

Did you add more dwell? OEM is like 1.9ms at 14v, you need close to 4ms to get them to work.

I have 3.8ms at 14v with mine, runs so much nicer than the Splitfire with a boss 1.1mm gap and at present 1.4bar of boost.

[SM514]

I just noticed I put this in the wrong category. My appologies.
I didn't. By the way, this is an R32 GTR almost all stock. Only the HKS filters and 3 inch exhaust. Stock ecu. So no adjustments possible. And I reached out to the company and they said it should be fine.
But that also would not explain why it still does it on the stock coils and ignitor.

[Dose Pipe Sutututu]

I would check the OEM earth points on the ECU (inside), check the voltage going to it and comb through and see if all the OEM earth straps are connected from body to motor.

Using a multimeter, check the loom on the coilpack. Say your electrical system measures 13.8 to 14.4 whilst running, when you measure the voltage at the loom it also must be close to that, yes there may be a slight voltage drop but that's normal.

[SM514]

I would check the OEM earth points on the ECU (inside), check the voltage going to it and comb through and see if all the OEM earth straps are connected from body to motor.
Using a multimeter, check the loom on the coilpack. Say your electrical system measures 13.8 to 14.4 whilst running, when you measure the voltage at the loom it also must be close to that, yes there may be a slight voltage drop but that's normal.

I did exactly that. Checked grounds and started to trace wires. But before I go too far into that, the ecu was right there. Easy work first. And this is what I found!
Can anyone identify the board?

[joshuaho96]

Looks like you might have shorted something. It shouldn't be possible to damage the coil drivers like this at stock dwell settings.

[Stixbnr32]

R35 coils wont work as far as I was told on stock ECU.

Like above the dwell settings need to be changed.

[Duncan]

so....the earth wire was switched with the power wire in the loom you bought, and now the ECU is fried. Perhaps talk to the people that made the loom, it is reasonable important to have the right wires in the right places

[burn4005]

That is basic QA for any manufacturing business to test, especially if it's hand made and not automated. I would not be happy. 

 

But as already stated, stock dwell times will impart less than a quarter of the energy required for design spark power. You need an ecu that has adjustable dwell. And if you're on a stock ecu you can't be doing anything too exciting power wise so r35 coils are overkill. 

Edited June 26, 2019 by burn4005

[SM514]

So the companies I have been working with, the supplier and the merchant, are both fantastic groups. They have been helpful the entire time. The custom harness came from the merchant and they are absolutely understanding. The ecu is bring paid for. No hard feelings. It was an honest mistake and we're good there.
The supplier said that the R35 coils are going to work but I will not get the full effect from them without the adjustment, and I understand that.
For now, I only have a stock ecu. Future plans certainly have a need for these as I will be building up this winter. My budget is far more forgiving if I do it a little at a time. ie. the woman isn't as surprised at the cost when it is drawn out over time
I went this route simply because the stock coil harness was crumbling and since I was going to upgrade anyway, now is a good time.
It is better this way anyway. I couldn't imagine if this harness ruined a new Haltech!

Thank you for all the help and suggestions!

[joshuaho96]

Stock dwell time on the ECU will work with R35 coils if you are running a mostly stock engine or somewhere near it. Dwell time increases only come into play when the  spark is getting blown out from excess pressure in the chamber.

[SM514]

Stock dwell time on the ECU will work with R35 coils if you are running a mostly stock engine or somewhere near it. Dwell time increases only come into play when the  spark is getting blown out from excess pressure in the chamber.

Excellent. Thank you.
As I get more into this thing, I'll have the ecu to compliment the rest of the parts.
This is stick for now. Just a 3 inch exhaust and hks filters. Nothing crazy

[Duncan]

4 hours ago, SM514 said:

So the companies I have been working with, the supplier and the merchant, are both fantastic groups. They have been helpful the entire time. The custom harness came from the merchant and they are absolutely understanding. The ecu is bring paid for. No hard feelings. It was an honest mistake and we're good there.
The supplier said that the R35 coils are going to work but I will not get the full effect from them without the adjustment, and I understand that.
For now, I only have a stock ecu. Future plans certainly have a need for these as I will be building up this winter. My budget is far more forgiving if I do it a little at a time. ie. the woman isn't as surprised at the cost when it is drawn out over time
I went this route simply because the stock coil harness was crumbling and since I was going to upgrade anyway, now is a good time.
It is better this way anyway. I couldn't imagine if this harness ruined a new Haltech!

Thank you for all the help and suggestions!

Well, massive thumbs up to the supplier that they took responsibility and corrected the impact of the issue with no problems.  That is by no means guaranteed in car aftermarket, so good on them.