To big of a drop in voltage at start up. Changing the battery solved the problem! Now the tach works immeadiately.
If you guys have the same problem check out with a new battery first.
(Got my new motorcraft for only 60 bucks!!!)
A forum community dedicated to Ford Mustang owners and enthusiasts. Come join the discussion about performance, builds, modifications, reviews, engine swaps, classifieds, troubleshooting, maintenance, and more!