What would cause a tach to twitch at idle? Misfire? I just reinstalled my monster tach this morning because the colder weather is screwing up the stock tach. I noticed my monster tach would twitch at idle from time to time. I'm using the signal on the tach output of my 6A. The other thing is that I dont notice it hapenning on the stock tach but I will verify that right now. Any thoughts?

Thanks, Ed

 

theres a blue plug that goes onto the one of your coils, make sure it has a clean connection. also does this only happen when the car is cold? my tach seems to jump around for a few seconds when i first start up the car in the morning... something about the coils acting weird when cold.

 

if you read auto meter's hidden facts. they're made to be accurate up high and they are known for twitching at idle, it's normal. the stock tach twitch is from old wires and connections it's a known problem with ageing sa/fb's

 

make sure you have a good ground too, i had irratic readings from my autometer shiftlight from a not so great ground connection, but yeah, they then to twitch a bit...

 

It does it hot or cold (the monster tach). I will double check the ground. It never happened before. I did switch to a different ground connection this time around. Anyways my stock tach does not work when it's cold out. After driving say maybe 5 min. then it will gradual start to work. Time depends on how cold it is.

Thanks, Ed