A while back my tachometer kind of stopped working it works at idle up to 1600 rpm and then drops back to 600 and goes back up progressively to 1600 but never goes above 1600 however the engine reved smooth and ran fine

Occasionally i will be driving and it will all of a sudden be working or i will start the car and when i rev it it will work superbly but only for a few minutes or untill i shut the car off again and then will continue its frustrating antics

I was wondering if anyone else has had issues like this and could offer possible solutions or acctual experiences

 

AHHHHHHHH, yeeeeaaaaaaaaaaaaaah.
I think you'll find your tach is fine and you need to look at the idle...

Is your tach movement at all related to your right foot?

 

this is a common problem...doing a search will help you in more detail...It is the solder joints failing on the back of the tach...

 

A fellow user on the board named FDjunkie sent me his write-up for the procedure of re-soldering the necessary connections on the back of the tach to fix this problem. I haven't actually had the time to perform the fix myself yet, but the write-up looks good. You could PM him and ask for the write-up perhaps.

Later
Fd

 

I have post a how to on this thread
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/tach-problem-490749/
You must have a basic electronic knowledge

 

I have the write up hosted on my site.
http://www.umsl.edu/~tch9gd/Tach.pdf

 

I am just about to begin this process. I have a jumpy tachometer as well as a mis-reading speedometer. Since occasionally both read accurately is it fair to assume I do not need to replace the capacitors and just re-do the connections. I would like to avoid re-soldering EVERY joint, is there a specific couple that are prime indicators of misreading speedo and jumpy tach? Any advice would be great.