So I'm trying to get my 92 miata running on ms3x. I am getting some engine sputtering/backfiring, but no start. According to the guy that built it, I am having an issue with crank signal hysteresis. He said he replaced the 100k pot with a 100k resistor per many guides and other ecu builders and has had no issues on any other miatas. See the composite log attached. Sorry if I'm not explaining this well, I'm still in the learning process. Any input on how to get this sorted would be appreciated.

 

Bump. Anyone? Really need to figure this out...Any help is appreciated.

 

How are your ignition settings? I had to flip my settings around before my sputters turned into it actually starting correctly. Have you adjusted any trim pots at all yet? That 100k resistor mod is only for a single pot but the others might need some adjusting for your car. I'd post your ignition settings first though. Here's a thread I had sync issues in and what all fixed it for me: https://www.miataturbo.net/megasquir...x-94637/page5/

 

I have adjusted r56, but nothing else. It didn't seem to make much difference. I'll post my ignition settings when I get home later. I'll read through your thread as well. Thanks.

 

Here are the ignition settings. Note that I have tried both rising and falling edge.

 

You need to make sure the trim pots on your expansion board are set right. It's written in the trubokitty guide: "Turn both R11 & R32 (6) turns to the fully counterclockwise. Turn R11 back 3½ turns clockwise. Do not turn R32 clockwise" I had to have mine less than the guide and Brian was saying people usually need to dial in more if anything. You might also see if switching your cam from "normal" to "inverted" just to see what your logs do. I'm not sure what NA's use.

 

No luck with that. R11 and r32 are for the cam signal, and my issue is with the crank signal. Switching the cam signal to inverted did result in more sputtering, but no start. I have another cas on the way to try to see if mine is bad.