[Guest]

I have a 1965 6000 rpm rally pac installed in a 1965 Mustang and at timest the unit will increase by 1000 rpm turning the ignition of an on will sometimes correct the problem or some times it will correct by its self.
I have an MSD ignition installed and have a tach adapter as part of the set up.
Please help.

 

[fdreano]

If its a repopped rally pack (Say the ones from Dallas Mustang) they had some quality problems. The one on the pictured convertible would go crazy about 1-2 times per week. It would peg and whip around until I slapped it with my palm. Finally popped it open and found a bad solder joint. Fixed it 7 months ago and no problem since then.