I just changed the tach in my 74 Duster. I went from a cheap 80s parts store tach to a nice Autometer tach that I got for Father's day from my kids.
Now the car idles smoother both in neutral and in gear, to the point that I will likely turn the idle down a bit because it went from 900 rpm to about 1050 or 1100 rpm. I know grounding out the tach signal kills the engine so it seems reasonable that the tach could mess with spark, especially at lower RPM. Has anyone ever experienced this?
Cley
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