E8 4AGE 20V intermittent trigger issue

[dk5293]

hi, have an E8 wired up to my corolla track car for about 5 years now. has been fine for the most part... until i fitted bigger cams, headwork etc. took it to the tuner for retune, which involved raising the redline and have found that over approx 7500 rpm it will intermittenly pop and buck on the dyno just momentarily then be fine again.

sat in the car and had the 'trigger count since home' window open, while the tuner ran it up on the dyno and saw that the count number would drop from 24 to 23 for the split second when it would pop.
doesnt seem to be a problem with the shielded trigger cable, we also chucked some capacitors on the COP's incase it was electrical noise from them. still did it. also opened up CAS- pickup and teeth looked fine and gave them a light clean up anyway, still doing it.

im on the verge of bringing the car into the 21st century with a new ECU and loom but thought its worth still asking this to see if anyone has had this issue with this engine/ECU combo and if theyres anything we might have missed in troubleshooting this?
Cheers