1997 DIYPNP turbo miata random tach drop
 

turbo miata randomly drops tach and feels like the rev limiter is active
I got a log of it happening but im stumped.

1997 miata diynp
ISR rs3871 on trackspeed manifold
NGK R5671A-7 Spark plugs gapped down to .20
switch in and out coil pack with another known good coil pack.
different wires

I sunk this car underwater before putting a built motor in it.
FYI the megasquirt was underwater for a good minute and then rinsed off in my kitchen sink.
I replaced the coil pack 02 sensor and cam angle right after this so these are semi new.
my tune and a log of the event is enclosed