COPs frequently go bad. Might have missed it, but have you rotated the suspected COP to another cylinder yet?

how did you test?

I haven't switched the COPs yet but I have a couple spares so I'll try that.

I used output test menu in tuner studio to test them.

You could just also swap 2 of the cops and see if the misfire changes cylinders with the COP.

^i second this method. Keep using the cops you've got, just swap the cylinders. That way you are not introducing new variables with a different Coil.

so you used test mode to determine all four coils spark, but #4 doesn't spark when the car is running?

Yeah, hence the confusion. I audibly heard all 4 plugs pulse like mad.

I'll try switching the plugs to different cylinders as fire/hornet suggested.

OK replace the COP on #4 with a spare I had and then started up the engine. I then unplugged the wire to #4 and the engine stumbled and then became smooth after reconnecting it. So I'm guessing that issue is fixed.

Now I'm trying to figure out why I have no timing advance. it will go from 0 to -1.4. It did give me crazy advance at start up to the tun of 24+ but then went to 0 and didn't deviate from that.

Also the AFR in TS and the gauge were matching for the first 30 seconds and then the tunerstudio AFR didn't move from 13.30, while the AEM gauge danced between 13-15(which I hope is a good sign it isn't running lean).

Do I need to go buy a timing light and figure this out properly on the timing issue?

And also why at the slightest throttle input it revs to 3.5k and hangs there, then slowly comes back down to around 1.4k and holds steady there.

Here is the small log I made if that helps.

https://www.dropbox.com/s/yd53lxkicq...0_18.17.19.msl

Pulled cyl #1 spark plug and tested TDC with the dipstick method. I think this looks right. It was a little hard to tell when it was perfectly TDC.

https://www.miataturbo.net/attachmen...ine=1399982163

So at least I know now that the base timing is correct, just need to figure out why I have no timing advance and the weird throttle issue.

Which MS are you again?

The MS can be put into a fixed timing mode (used to set base timing). Are you in that mode?

MS3x. And I don't believe I am in fixed timing mode. Timing is set at 10 in TS.

You have to set timing to fixed 10* when using the timing light. You cannot keep it on "use table"

So fix timing at 10, start the motor up, and ensure with a timing light that it matches? Sorry never used a timing light before so I just wanted to double check.

Yes, basically. There's a writeup on it actually. Even on m.net garage section there's a how to on doing this, the only difference with ms is instead of "locking" the ecu into 10* with jumpers, you simply go into TS and timing settings and switch the drop down from "use map" to "fixed timing".

Then you check with timing light and depending on how much its out you adjust either by rotating the cas, or changing the "offset" in ms until 10* = 10*

Thanks Vlad for spelling that out simply for me. There is a vast amount of information I'm trying to absorb since I am starting from knowing nothing(literally) I'm a little overwhelmed by it all.

And please don't forget to set the timing setting back to "Use table" again afterwards...

hahaha yep, unless you want your car to shoot flames like a boss :giggle:

Tempting, all cool cars as taught by the car mod gods of 2 fast 2 furious, shoot flames, but the OCD in me knows I'd melt my rear bumper, so no!