Has anyone else had this problem? I put in a msd sci box with a ss coil. Every once in a while my tach jumps around and goes crazy. I soldered my wires and heat shrunk them. The engine doesn't seem to bog or change but the tach goes crazy. Is it my dizzy or is the surging common with msd?

 

I have the same Issue but I took off my MSD coil and 6AL and still does the same thing its not affecting the engine but the tack goes nuts at around 8k falls back to 1k and sometimes just turns off. I installed a 5" tach and connected it to the tach signal wire on the fender but have not had a chance to run the car to see if the 5" tach looses signal.

 

so you took off your 6al and msd coil and it still does it? Interesting maybe it's just my dizzy?

 

Yep, I already changed my dizzy once from my buddy car still did it and it does not happen to his car, But remember it does no affect the performance of my engine but it is aggravating at the track when the RPM needle goes nuts.

 

maybe it's the cluster then or my tack signal wire. I'll double check again.