[Saldua99NB]

Ok after 2 weeks of troubleshooting i am at a loss... any help would be appreciated.

To verify spark I used a timing light on all cylinders while cranking and then again when running.

When Cranking the timing light flashes when connected to all cylinders.

When running only 1&4 cylinders are showing spark using the timing light.

Car runs really rough and i have to give a little gas to keep it going

Timing has been verified and set

When reverting back to stock ecu all cylinders spark when cranking and running (this shows coil packs and ignitor should be good)

Also because i see spark with the speeduino while cranking i believe that should be good as well. I am thinking i may be missing something with my tune.

I am using miata 99-05 decoder with trigger edge rising and secondary falling.

If there are any setting that i may be missing that may cause this or anything i could try please let me know. Thank you in advance.

speeduino is v0.4.4 board and i have tried with multiple firmware versions. The current version being used with the tune below is 202005

[jonbill]

coil dwell?

[LPG2CV]

Dwell was also my first thought.

[Saldua99NB]

Thank you both for the idea. Below is a snapshot of my current dwell settings. What should i adjust these to?

Also forgot to mention in orignal post that my car dash tach does not work when car is running but it shows in tuner studio.

When i use my stock ecu dash tach works.

[theonewithin]

You will need to do research on how your dash works in regards to tacho and then do whatever you need to do to the Speeduino to satisfy that.

DIY projects expect you to do the leg work.

[PSIG]

Decoders should have both primary and secondary trigger edges as either Rising or Falling, for most setups. I'd try 0° and both Rising, then check if the timing is correct. Else try both Falling. I haven't tried the Miata 99-05 decoder, so give it a shot. One combo should put timing right-on or very close.

Is that waste-spark coil packs?

David

PS: Please don't post screen shots of settings. Just post your tune. Adding a log of the issue is very helpful also.

[Saldua99NB]

Thank you psig for your response. I will try and get a log of cranking and running tomorrow. I did very quickly put both to rising and falling and still had the same issue.

I took my speeduino out of the box and noticed when tuning 2 spark LEDs are not lighting up. So it looks like no spark signal at all is being sent to ignb. Could this be pointing to hardware issue with the speedy or could it still be the tune.

Disclaimer, I pulled this speedy out of a wrecked Miata so I am not familiar with who or how it was put together.

[SpartanSv]

99 miatas are waste spark. You should only be using 2 ignition outputs.

[Saldua99NB]

Yes i apologize i was not very clear in my last reply.

I have it setup as waste spark. And only 1 spark light is lighting up. I will be running a log in a bit. Thank you.

[Saldua99NB]

attached is a log of cranking and running.

I took out the spark plugs and verified by using the hardware test that they are all firing.