My tachometer is reading about 2-2.5 times higher than what my real RPMs are. I know it gets the signal from something in the spark distribution system, and if this piece is malfunctioning It will give a false high signal, but I forgot what part it was. Anyone have any ideas?

 

i've always heard its the msd box that causes it. but once it happens i don't know if the tach is fixable. my 91 did the same thing. happened slowly over time after i added a 6al

 

Is this in just newer Camaros? I wanna run a 6AL on my new engine, but I don't want the tach all funny.

 

I can tell you 88 T/a`s have the same problem! tachs are just to sensitive as quoted by a MSD phone tech! also a shorted plug wire or arching from the coil tower(external coil) can cause alot of electrical interference

 

i think i read something about msd having a tach adapt for this but never called to ask