I think one of my COP's has gone bad. How can I tell if it has/which one?
 

I've got a MSPNP in my car and I just reinstalled my COP setup (standard miataturbo setup) and the car is definitely not running right.

There's a lot of stumbling under 4k and still some above. I've had one of my coils fail before and it seems very similar. I've attached a .msl log I just took this evening(I had to toss it in a zip archive for the file uploader to work).

My question is how can I check which coil has (possibly... probably) failed and can the log file help me find which one it is?

I'm pretty newb when it comes to tuning, so any help is greatly appreciated!

https://www.miataturbo.net/insert-bs-here-4/my-adventure-filled-road-trip-aka-careful-when-you-load-your-old-msq-41933/

My blown COP thread. Any of your dead coils look like my dead coils?

Sort of. There's not as much separation between the bottom two pieces as yours, but the pic below shows the one coil that I found separation on.

http://farm4.static.flickr.com/3173/...71cd1a9b_b.jpg

I tried banging it back down (using a spacer over the ribs) but that didn't do anything. Maybe putting a heat gun on it for a while and then some smackin will put it back down, but I realize that this is a long shot to actually fixing a damn thing.

Can my MS log file tell me if it was the #4 cylinder coil(the one pictured above) that was crapping out? I'm looking at it now, but I can't see anything yet...

One at a time, pull the connectors off of the cops with the car running.

If the car stalls / significantly changes how it idles when you pull a connector, then you know that coil is working.

When you pull one of the connectors and the behavior of the car doesn't change, you've found your problem child.

Well then. Thats a simple and effective way of checking.

Thanks man, I'll do that now!

The car barely wanted to start and wouldn't stay running at first.
I see my fuel load is at 100% before cranking and I'm thinking that can't be right. Yes/No?

I loaded the stock tune Braineak sent with the MSPNP (and changed the dwell settings) and that got it to turn over and (somewhat) run. I have to give the car at least some constant throttle to keep it from bogging down and dying.

Looking at the log I just took I see that my MAP and Final pulse Width inversely correlate with RPM (where MAP and PW spike, RPMs dip) so I'm wondering if/how they are connected.
I'm also seeing random spikes in my MAT (mani air temp) and I don't know what's up with those. I even had two MAT spikes before I started cranking the eninge.

Now I'm wondering if the issue is coil related or perhaps fuel/tune related.

Attached is the log I referenced in this post.

fuel load% = kPa

ok... so fuel load = kilo-pascals. Sorry, but I don't understand what you're getting at.

~100 kPa is atmospheric.

Alright. So the 100% fuel load before cranking is ok. Good to know.

I'm gonna try to keep it running while letting VE analyze live do its thing for a while. Maybe it'll do some good.

UPDATE:
Car is now idling ok. It's idling at about 1300 which isn't great, but I don't need to give it any gas for it to run, which is nice.
I'm gonna take it around the block a few time to see if I'm still getting the stumble I got last night after initially installing the COPs.

Before I took it on the aforementioned test drive I restarted it and now it has developed a popping sound. I took a quick video of it and the link's below:
http://www.youtube.com/watch?v=hQT8H...er_profilepage

Now I'm back to thinking a coil is bad since there was no change made to the tune between before the popping started and after.

Fun stuff.

One at a time, pull the connectors off of the cops with the car running.

If the car stalls / significantly changes how it idles when you pull a connector, then you know that coil is working.

When you pull one of the connectors and the behavior of the car doesn't change, you've found your problem child.

Hope this helps!! :laugh::laugh:

Actually, in the case that it isnt misfiring on every other rotation, pulling the bad coil connector will cause it to "change the least"

I swear I've heard that advice somewhere before... lol

I couldn't really do that earlier since the car wouldn't idle, but I'll give it a go.

Pulling 4 and 2 don't make a difference.

Pulling 3 and 1 cause it to stall.

Then you're running on two - move the good coils to bad cylinders and see if the bad cylinders start firing instead - if it does, this will completely isolate the "bad" coils as "bad" and you'll know for certain that you need 2 new coils.

Finally - since it sounds like bad coils was only a symptom of the problem and not the problem itself, it will be time to do a little more investigative research

Ugh, now I just started it up and all 4 coils are firing (pulling each connector slows the engine but it doesn't die). Switched 1 & 3 onto 2 & 4 and pulling the connectors does the same thing (slows the engine but no death).

There's still some faint popping sounds so I'm sure I'm not at 100% coil/ignition wise, but at least the coils aren't falling on their face for the moment.

Thanks for your help fooger, I'm going to order a new set of coils as soon as I see a decently priced set.
I'm pretty sure what killed one of my coils last time was the fact that I was running a stock ECU, therefore overdwelling them. I'm still on 3 of the 4 that were subjected to this so I wouldn't be surprised if the overdwelling has caught up to them. The new(er) coil was the #3 coil that passed the 'pull the connector' test you prescribed.