MS3 cutout and sync loss. LS2 coil failure or ?
 

A few weeks ago the LS2 coils I've been running started to cut out. Long story short touching the harness made them come back. So I made another one from OEM parts and a weatherpack.

Now yesterday at AutoX the ignition cut out near the end of my 3rd run and the check engine light came on. The event happened at 6k rpm ish. I didn't have data logs running at the time and thought it might have been a knock event or something. I checked everything in the pits that I could. It felt like someone was flipping the on/off switch on my ignition. It still ran and idled when the rpm came down. It got me through the grid and all. I decided to try a 4th run and in the second turn at high rpm it cut out again so i coasted the course idling. This time I have a datalog. It was miserable hot out and intake temps hit 140s. I figured the coils got hot at first.

It runs and drive fine it seems as long as high rpm is avoided. When the cutout happens the AFRs seem to spike leading me to believe the ignition is cutting out not fuel injectors. I will add I swear the Walbro fuel pump is louder and nastier sounding at "key on" than it use to, but I may be hyper sensitive to things now.

The only things I've changed recently:
-new OEM to weather pack harness.
-started using launch control
-new brakes and RS3 tires (just on the list)

Here is the last run datalog.
Attachment 175263


On the drive home we replicated the cut out.
Attachment 175262


Not too sure about these setting. I swear I saw somewhere on the site it should be set to "going low" at spark output. I also think I saw that Spark Duration can go to 2ms.
https://www.miataturbo.net/attachmen...ine=1467051511




Also am I wrong that all the "engine light" stuff is off? Not sure what happened.
https://www.miataturbo.net/attachmen...ine=1467051511

Can you capture the sync loss in a composite log?

Here is a vid of it revving in the garage. I'd drive it, but there is a decent storm going on and would like to not be stuck in it if it goes wrong.

Absolutely, give me a lunch break and google search of how to do it and I'll be back

Ok so I never used this before and am not sure what I'm looking at. Here is a short pass times 2 and a sync log as well.

EDIT: the sync log didn't get weird until almost the end. It didn't want to replicate the issue for a moment. What else is used for sync on a VVT motor. crank and cam I thought

I don't see it showing a sync loss on the logs posted. This is usually indicated by red lines on the lowest trace of the log. But one of the logs MIGHT have shown some noise on the crank sensor feed. Try adjusting the main board VR trim pots.

I'll look I to finding those. I assume that's a mechanical thing inside the ECU. I did find that the crank position sensor was at its farthest edge of its range last night. A drivers licence and VA ID are oddly .059 in according to my caliper. The largest feeler I have is .032in so set it to that. No fix. I found a spare cam position sensor last night and swapped it. I'll try a drive after I Google the pot stuff and finish coffee.

Thanks. I have a couple more logs I'll drag out. Being a high speed logger it seems to not record the whole period of time, but just a window over and over. I might have on from last night I caught just as it started to break up sparks.

I dug up a spare cam position sensor and boom it seemed fixed. Couldn't get it to replicate the issue all day. Had to drive an hour out of town and did it once I think and then a couple times on the way back. I guess I'll have to open the case and mess with the pots if I can get my hands in a scope.

Cam Sensor Issues / Fix - Spec Miata Rules & Competition - Mazda Racers

Anyone having sync loss issues with NB ignition pickups has to look at this "fix" that the Spec Miata guys have come up with. Mind you this is happening on factory ecu's so the issue is global, not just with Megasquirt.

I found it good reading. Thanks to PatCleary for bringing up the link in another thread about sync loss issues.

Cam Sensor Issues / Fix - Spec Miata Rules & Competition - Mazda Racers

Anyone having sync loss issues with NB ignition pickups has to look at this "fix" that the Spec Miata guys have come up with. Mind you this is happening on factory ecu's so the issue is global, not just with Megasquirt.

I found it good reading. Thanks to PatCleary for bringing up the link in another thread about sync loss issues.

So far it seems the connector pins are the culprit. Tested the sensor with a meter and screwdriver and the first one did odd things, but my seemed okay. By odd I mean it would lock to one voltage until bonked with a screwdriver. Then I tweaked the connector pins with an eyeglass sized flat head. After swapping and fiddling with the pin spring pressure I can't replicate the cut out.

Just re-pinned the connector and seems to be fine. So chased two problems and new sensor and new pins solved it.

I seem to be having this issue or at least seems like on my 01 on stock coils. I seem to get it while at load, check engine light will trip and the car will just die and eventually coast to a stop. Leave it off for a second and it will fire right back up. Anyone got any input?