Inaccurate Tach

[killerFatty]

So my tach is having some weird problems, but first some important info. The needle in the orginal tachometer broke when I was fixing the circut board some I glued it back together and it worked alright. Then finally the glue gave out and the needle fell apart inside the gauge cluster. So I took apart the cluster and swaped in the tachomoter from my other parts cluster and it worked great... for about two weeks. Then I noticed that it looked like my car was idleing at 200 rpm, which is near impossible. I looked over the engine and everything was fine and the car was idleing normally, just the tach read around 200. I thought whatever and kept driving and I noticed that the shift point were lower than normal, and my car normally shifts at 6000rpm at WOT and now the tach would read around 5K at WOT, but the MPH at which it shifts are the same. Right around 48 in first and 80 in second. Now it has got worse. When I'm idleing it says I am at 0rpm and when I let off the gas the tach drops really low, and it looks like the engine shut off, kinda like a hybrid. There is no mechanical or performance problems, so it's just the tach that is acting funny. What would cause this?? any ideas would be greatly appriciated. THX

[lexfourcam]

Id check all the connections and cables on the back of the tach because something could've came loose.

[killerFatty]

Ok I will tonight, however my tach has now stopped moving completely. It just rests at 0 all the time

[steve2006]

If you red line every shift I'm surprised your engine and transmission hasn't died too! :whistles:

[killerFatty]

Umm thx for that helpful reply... I definetly don't redline it every shift, I was just using that as an example for the shift points.

[steve2006]

Sorry just my Brit sense of humour, the tach mech is very delicate and may have been damaged when you replaced the needle,given the previous problems it may be better to get a known good replacement from a breaker.

[dcfish]

Find a direct replacement guage.

[LA1]

Have you tried the pulling on the needle trick? If it isn't working you don't have much to lose. It is what I did on mine when it was acting similar (not working, staying at the highest rev point that is lower than it should be, showing 500 rpm while driving 65, etc.)and it is working fine now....knock on wood

I posted this a couple weeks ago but just in case here it is:

While holding the needle

-pull the needle out until it makes a light pop or click

-turn the needle right until it makes a click

-move the needle back to zero and let go, it should stay there

-move the needle up and let go and it should fall back to zero