MS2 Idling with only 1&3 cylinders?!? 1.6 '93
 

I installed MS2 to my '93 1.6, and car starts and idles with only cylinders 1&3. I have toyota COPS.

- I can see spark in all cylinders when car is idling with extra coil+plug attached to harness.

- Today I also tested injectorclip signals with lightbulb to injectorclip, one by one. I cranked (coils not connected) and found bulb glowing in all 4injectorclips.

- I can see that 2&4 is not working, because when idling, I can remove clips from 2&4 coils without affecting to idle.


I'm confused, what the fuk!! Suggestions how to continue troubleshooting?? I still suspect that engine gets no fuel to 2&4 cylinders..

Your car is likely wired for sequential injection already. Mine was a California car so it was. Check if 2Y and 2Z are populated, if they are you need to run leads from those wires to INJ1 and INJ2. I cannot remember which goes where. I had the same exact issue!

If only 2U and 2V are populated, then check your leads in the megasquirt. There might be something wrong with the INJ2 circuit, which drives Injectors 1 & 3 on a batch injected car.

Injector wires are same in 1&3 and 2&4. So my car is not wired for sequental.

Check the connection coming from 2V if 2&4 dont have fuel. And double check the soldering/wiring of the INJ2 (or whichever injector driver is hooked up to 2V) circuit. 2&4 are both run off of 2V

Testing, testing. I tried to put cops wiring opposite, from 1->4 to 4->1. Still running with 1&3. Okay. Next I removed fuel rail and checked is there really coming fuel when cranking, yes, about same amount from each injector.

https://www.miataturbo.net/attachmen...ine=1370606619
https://www.miataturbo.net/attachmen...ine=1370606619

More tips?

You have fuel, you have spark, it should go bang.

Check for compression on all 4 cylinders?

Compression was 180psi in 1,2 and 185psi in 3,4. No problem in there.

The only thing left is ignition timing. Are 2 & 4 firing when they're supposed to?

I have toyota cops wired like this:

https://www.miataturbo.net/attachmen...ine=1327066127

If you're running the factory harness then you have triggers for only two coils, i.e. wasted spark. I know you actually have four coils, but there's only two wires from the ECU. Try changing to wasted spark in Tunerstudio (Ignition options tab/ number of coils.)

I think this is the correct answer, I'll test it today when I get new car laptop, old one just broke down..

Car works now, the reason was it was set to seq spark. With waste spark it runs with all cylinders. Thanks all!