99 N/A Miata- MS2 install-blowing men
 

This is a Custom built MS2 I picked up from Thirdgen 2 years ago, I had it running last year N/A with no real issues for about 6 months. Then I went back to stock ECU to get inspected.

A few days ago, I tried to reinstall it with the old tune I ran last year and upon startup in ran on 2 or 3 cylinders for about a minute then it turned off...No more spark...coils blown. It ran rough but I was able to set the timing trigger offset (9.0*).

I hooked back up stock ECU and and got new coil packs and ran it for a week. No issues, no engine light, Cat didn't seemed clogged or anything.

So I tried to reinstall it again today and make sure all my settings were correct, I copied the same settings DIY had on their website for 99-00 miata.


Well it ran for about a minute pretty well, fairly rich, but firing on all cylinders, then after about a minute it just shut off. No spark again, I had felt the coils to make sure they weren't getting hot after 30 seconds of running and it seemed fine, then when it had shut off, they were pretty hot when I touched them again. I'm guessing I need another set of coils now. :vash:


1. Rising edge VS Falling edge-DIY shows to have it set to rising edge for stock 99 coils. Is that right? I know having it wrong will probably blow the coil packs....

2. Inverted vs non-inverted spark - I don't see a setting for it, I assume it goes under the "99-00 miata" spark setting. I found an old thread where CJerginan (almost) blow his 99 coils because of being inverted, instead of non-inverted. If my setting was on "going high" does that mean I ran inverted spark and subsequently popped the coils?

3.Firmware- I changed laptops and I remember seeing somewhere I had originally ran it on a 64 bit but the new laptop was a 32 bit so somethings showed error messages but I was able to connect and get all the sensors to read so never really thought it mattered much. Pretty sure it is v2.6.14 for MS2 I think. Thirdgen had given me a CD with the firmware he said he used but my laptops don't have CD drives so I just downloaded from DIY.

4. The harness had a couple wires come loose that I had to reattach, so I assume that means other connections could be compromised. Could an ECU short/bad connection fry the coils?

I uploaded the MSQ I tried to use today that blew the coils. Any help would be greatly appreciated.

Also is it worth trying to keep the stock coils? $80-$100 a pop to keep making the same mistake is really starting to piss me off...would it be worth it to find a COP setup and not have to deal with this shit anymore?

EDIT: Not Reverant built

You should probably first verify if any mods were done to the spark output - https://www.miataturbo.net/megasquir...circuit-33964/ comes to mind. After that you can make sure you've got the right spark settings.

Thanks, I'll pull it out tomorrow and try to figure out if it has those mods or not.

Don't use a Reverant built unit with DIY settings. He deviates in some things. Do you have the original tune from Rev?

BTW: Rising vs. falling edge trigger will screw up your timing, but shouldn't kill your coils.
Output going low vs. going high will likely kill your coils if you get it wrong due to over-dwell.

99 should be rising edge, coil output should be Going high on my ECUs.

this.

this.


Although, he should have been using going high as well on a DIY basemap (right, bond?), so it shouldnt have blown coils.

I had "going high" and "rising edge" in my settings yesterday when I blew the coil packs.

My first attempt about a week ago, because it was running so rough, I believe I changed to "falling edge" in hopes of something happening but nothing did, then eventually it had no spark at all after about 1 minute of running on 2 cylinders.

I pulled the board out just now and I'm trying to compare it to what is in that "better spark output circuit" thread. Keyword: TRYING. I know f-all about circuits.

yeah it really depends on how the output circuits are built. rising vs. falling shouldn't matter.

Post pictures, we can point out anything that looks odd. Top and bottom. And expect us to ask "what does this chip part number say?"

https://www.miataturbo.net/attachmen...ine=1453843821


https://www.miataturbo.net/attachmen...ine=1453843821


https://www.miataturbo.net/attachmen...ine=1453843821


https://www.miataturbo.net/attachmen...ine=1453843821

Uhm...this is not one of my ECUs.

Ugh.. yeah, that's a bit hacked up.

I don't know why I thought it was a Reverant unit, I have had it for a while. I went back to the old thread and it is in fact a Custom built unit, not by Brain or Rev, I'm guessing Thirdgen built it.

https://www.miataturbo.net/miata-par...o-gauge-82241/

I need to contact him and see if he has an old MSQ from it.

I really don't know what to do at this point...I want to think something is wrong with the board because I had run the same tune last year for months without issue. I'm just not electrically competent enough to figure it out myself.

'99 coils definitely need their input going high. So, as long as your spark output circuit is not inverted for some reason, going high is correct and with that and a 2.6ms dwell there is no way you should be blowing up coils.
You are running the same tune that worked before - right? Then going high is definitely the correct setting.
Maybe you have an electrical short somewhere pulling your coil outputs high?

in case someone wonders why we dont build v3.0 MS2s anymore...

MS3X from Braineack, then swap to LS coils for about the same price as new 99 coils.

Yes, loaded the same tune I ran March to September last year. The settings were going high and rising edge.

That is my main worry. If there is a short in the board or a bad connection somewhere causing the coil output to go wacky, then I'm not sure I would ever be able to figure it out. I'd be willing to sell this unit cheap to someone who thinks they can fix it and put the money towards a MSPNP for peace of mind, or a MS3x from Brain/Rev.

those spark outputs should be "going low" or normal. not inverted.


as bad as that MS looks inside, i bet it's totally fine to use, you just need to understand how it was built and what is going where. It could be an early unit built by Frank or someone else senior here (maybe even cjernigan). It's using the OE NB input circuit that AbeFM figured out and it's implimented in a way that Frank used to outline.

You are saying my board is currently set up to run "going low" or it SHOULD be setup to run "going low"?

I'm doing research on it, thank you for all the help so far.