I've searched and I think I might know what it is, but not 100%
I have what feels like a grounding issue on my 91 1.6 with an MS2 (bought second hand and supposedly built by Braineack), 460cc rx7 injectors. The problems at WOT became (obviously) more noticeable after throwing an SC at the engine but I've had this issue since day one.
I cleaned up all my chassis/engine grounds, even did the one in the trunk that bolts up next to the battery. Still hasn't solved it. My adapter harness had 1 spare GND lead not soldered to anything so I went ahead and ran a 14g wire from it directly to the battery. STill didn't solve it.
The problem comes on at WOT as well as part throttle (though less common) and many times as an idle droop. If it happens at idle it tends to happen at the worst time and leave me stuck in an intersection until I can get the motor to recover or die and start up again with some luck.
I've got logs of the Idle dropping out:
And here is a WOT situation. When it happens it's just a quick hickup and then I get a misfire when it recovers
Only thing I haven't done is try running a power lead from the battery to the ecu. I've tried turning on the noise filters as well.
I have read there is a small capacitor that could be related to the issue.
Any help is appreciated,