Adding an optocoupler to the harness might be tricky, that is usually done inside at the circuit board level. If you've removed the factory 'condenser' (capacitor) that is usually located near the factory igniter, it might be wise to replace that. Also replace the spark plugs with factory ones unless your tuner has a very good reason to use different ones. I would also do a deep dive into how the ECU measures the crank trigger sensors, and how to check if it has detected trigger errors or crank sensor errors. If you see any spikes or flat lines in the ECU's calculated engine speed when these misfires are happening, worst case scenario the ECU might be seeing bad signals and doing wrong things like firing the coils too early or holding the coil trigger signals on for too long (which could explain damaged coils). I'm not familiar enough with Link ECUs to know if trigger errors or noise/interference problems are common, or how they respond. But it might be wise for you to spend some time learning about it. Also, check the wiring harness near the fender and double-check all of the splices and connection joints. Both of those problems have caused misfires for other rx7club posters in the past.

 

check your crank sensors, you may have them plugged in backwards...why in the world mazda thought it would be a good idea to make the plugs fit both sensors is beyond me. i usually paint dots on them to make life simpler when i put them back together.

i'd also verify the timing of #1 trailing with a timing light, the plug wires could be swapped between #1 and 2, swapping the leadings causes no issues but swapping the trailing is bad, running in boost with it like that is asking for a blown motor. the car literally only needs the leadings firing to run 99% normally. if trailing are swapped or firing prematurely for whatever reason then you will get preignition, which by the sounds of it you are.

before potentially creating more problems always start with the simplest things to check, that has always been my rule. almost all problems usually are extremely simple and often overlooked.

 

So we tried a r35 coil conversion full custom loom made which was going on another of his customers cars and the car was still pinging as soon as boost started building, when he put it on the other car it worked fine

Timing and crank sensors have been checked and replaced and checked again

I’m pretty sure it’s an electrical noise problem, I have found out today he has used a 4awg wire to relocate the battery so thinking of changing that to 0 awg to hopefully helps in some way

Last shot is a ECUmaster PMU, but don’t really know if that would help in this case


we had the car on the dyno and took logs when the pinging would occur and sent the logs to link to deep dive into and they came back and said everything seemed to be fine

 

On another thread, a coolant temperature sensor was found to be faulting.

 

what was the issue he was getting ? Similar to mine ?

 

This was not it, but a similar issue. Turned out his MAP sensor vac line was not hooked up.

https://www.rx7club.com/general-rota...mp-fd-1168486/

 

I could not find the thread yet, but the guy was looking at his ECU readings on his laptop, using, I think, datalogit, and the readings for one * of his water temperature sensors was going haywire. He replaced the sensor with new. It was unique in that it might not have been discovered unless he had been running the datalogit.

(* there are at least two).

 

I think this is the one:

https://www.rx7club.com/3rd-generati...1167435/page3/

 

Here is another one. It seems each guys problem has a different source.

https://www.rx7club.com/3rd-generati...1168893/page2/