Hi Rob, Sounds like your tach lead (green connector)might be plugged into your fuel pump test lead (black connector) behind your alternator. The problem is people think these two plugs belong together. If so just just unplug them.
Bruce Alred
Hi Rob,
My tach reads exactly double the true engine speed. I also would like to figure this problem out. It would seem that our problems are related. No complaints regarding these items, but what else could be at fault here. Let me know!
Dale