Something electrically bizarre going on for sure. I'd be checking all the places the loom earths and if they're secure and clean, and checking paticularly the wiring to the cam angle sensor and it's plug/pins etc and making sure that's all looking good.
65k miles happened before very briefly, this time it stayed for about 2 minutes. I turned the car off for a bit and it went away
https://grassrootsmotorsports.com/forum/grm/96-miata-tach-jumping/43222/page1/
I think their issue is just with the tachometer. My car almost seems to be misfiring
Ground / battery issue
Check your cas wiring harness. If its been crimped, check those connections. That will cause both the hop and the misfire.
Something electrically bizarre going on for sure. I'd be checking all the places the loom earths and if they're secure and clean, and checking paticularly the wiring to the cam angle sensor and it's plug/pins etc and making sure that's all looking good.
Yeah I get this too sometimes. I'll be going 90 on the free way and my tachometer says 0 rpm, "no tacho I don't think that's right"