Lately I've been having problems with my tach. When it's cold out it either works intermittently, or not at all. I just got back from work and the tach was not working at all (It's 50 degrees out right now), and as I got closer to home it was up at 3k and not moving. (Untill I turned the car off) Sometimes I'll be driving when it's cold out and the tach will be really sluggish, and sometimes get stuck. Does anybody know what could be causing this?

 

yes i just bout my car a couple weeks ago and had the same problem i guess its the oil mazda used in them turns into a gel like substance when its cold out and untill the interior really warms up it will start to work

 

sounds familiar with my 83 took a while some mornings eventually the take played up jumped everywhere so i got a aftermarket one..

 

lol i have an 83, live in florida as well, & with the recent cold fronts here ("cold" not really, 55 degfrees or so?) my tach sticks. after about 20 minutes of driving it works fine. i wouldnt worry about it.

 

That's correct. I guess the problem becomes worse when after the stuff ages for a while.

 

My tach started doing that just before the trailing igniter went bad.

 

The trailing igniter is going down hill.
.

 

Any Ticking Noise when the Tach starts acting up?
If not then I have to agree with the Trailing Ignitor starting to fail.
Engine Temps will also play a roll on how the Ignitors Re-Act when they are about to go Bye-Bye.
Sometimes we get lucky with this warning and have time to replace them. But not always.
When the Tach starts to act up, exchange the Leading and Trailing Ignitors and see if all is well.
That will be the Answer you are looking for.
i.e. Bad Tach or Bad Ignitor.

And don't forget to use some Dielectric Grease between the Ignitor and the Distributor when you reassemble them. That will help with Heat that our Engines Produce.
Kinda like putting a Fan,Heatsink and CPU together on your Computer.
Radio Shack has this stuff for like 3 bucks a tube.
Good Luck
sgieldon
steve

 

There is some sort of ticking noise when it is acting up, but I can't quite hear it good enough to define it. And the Tach acts up, regardless of engine temperature, only when it's cold inside the car. It doesn't matter really, I can tell what RPM the engines turning by listening to it, so it's not that important. I'll check the ignitors though.

 

For SAs, the tach gets its signal from the leading ignition. So wacky tach doesn't always point to trailing igniter.

 

When the tach is not registering, check for spark at the trailing side. What a concept,lol.

 

Fixed it, Trailing ignitor was loose. Now The O rings between the housings and the intake manifold are leaking.

 

Was the screw loose that attached it to the dist or the connections at the ignitor?
I presume on your new found problem that you are leaking coolant? Don't take any chances on driving it until that is fixed.