The other day when I left for work in the morning I had no tach, but then after about 4 miles into my drive I noticed the tach slowly beginning to work, it would climb about 100 RPM every 5 seconds, but once I went about another 2 miles It was reading the correct RPM's but responding too slowly. It is working fine for me now but I was just wondering if anyone else had this happen. The only thing I can think that it would be is maybe with it being about 20 degrees in the morning, there might have been higher resistance in the ignition wires, if the tach is electronically driven that is, other wise if it were a cable driven tach I would think it would either work fine or not work at all. Also I just swapped the plug wire with new ones from my 83 12A, do you think that could have had an affect?

 

very common problem when the weather gets REALLY cold in the S3's. to my knowledge there is no cure other than allowing the electronics to warm up gradually. once warm, the tach will work just fine. i've been through this on an 84 SE that i had about 10 years ago. was a very common occurance when it was super cold.

 

happens to me too. and yep only way to stop it from happening is to have the passenger compartment stay warm. just dont burn your car down.

 

+1 on the slow tach. By the time I get to work, it's working fine usually. This is in like 30 degree (F) weather. I won't drive it colder than that usually. Actually, my car is not a daily so I think the tach sticks a little more than usual for me... It almost seems like a drop of machine oil on the pivot point would help things out.

 

Doesn't the tachometer get it's signal from the trailing ignitors? Perhaps there is a problem with them?

 

Nahh... When you see it happening you can tell it's a mechanical issue. I think the needle pivot just gets dirty over time. I drove my car to work today, and just now at lunch the tach would not go down to zero after shutting the car off. I slapped the dash a couple of times and it would move downwards so it must just be junked up or the lubrication has dried out.