[STEVE-O]

Have an MSD 6AL and Roush 402 / Holley carb installed in a superformance built in 2008. MSD rev limiter is 7000.
Weird issue I've noticed recently with the tach.
As the engine revs to 4000 rpms, the tach seems to lose its reading and the needle begine to drop. Even though the engine is running OK.. no stumble / miss etc..
As the engine goes back under 4000, the tach starts reading again.

Sounds like some kind of lost signal issue. Anyone else notice anything like this?
Symptom of MSD going bad?
Any other ideas?


Thanks