Just got my first car, a 84' gsl-se, car runs strong and I love it. My problem is with the rpm tach. When I first got the car it worked fine. Then a couple of days later it would start working after about ten minutes of running the car. Now its stopped working and is stuck at 20,000 rpm. I don't know what the problem is, please help me out and tell me the problem and how to fix it.

 

stuck at 20,000rpm?? thats one big tacho...

the needle might just be stuck, im not sure what ur ment to do but i would take of the plastic on the front of the tacho and just give the needle a little budge to see if it comes unstuck

or.. it could be the wires on ur trailing coil. they might be dirty and have **** connections.

 

Could be your trailing ignitor.....

 

Im sorry I was half a sleep I mean 2,000 rpm, thanks

 

I just got mine, and the tach only works SOMETIMES.

Does this have anything to do with it being like 0 degrees outside here?

The first day, it didn't work, and then 5 minutes into driving it started working.

Now, it works when it WANTS to.

I am wondering if it is a faulty connection......and, how would I go about fixing it? Everything in this engine bay is new to me.......

 

Same thing happened to me. Replaced trailing igno\itor and problem fixed.

The ignitors are the two black boxes on your dist.

 

What if the tach doesn't work under 10 degrees but fine otherwise, what causes that?

 

Common problem for these cars, actually, and is probably due to the thin oil that's used to lubricate the needle mechanism on the back side of the instrument panel. My 84SE (164k mi) does the same thing during cold winter months (here in AZ, that means 40 degree nights), and once the engine warms up, and interior warms up, the needle skips up to speed and functions as normal.

No problems with engine performance or trailing ignition, since the engine runs fine before and after the needle 'catches up'.

I'd say that you can probably take apart the instrument panel and see if the needle is pressed in too far, or find the cause for it being stuck. Once you find out, post back - I'm sure there are others that suffer from this.

I never fixed mine, just live with it during winter season (which is only about 2 months here). HTH,

 

yea i can live with it, it doesn't take long for it to get warm enough for it to work. I'm not pulling that whole thing apart just to fix it.

 

Mine does it when it's cold out too, but once I get some heat on it then it will come to life. I always figured it was some metal part that shrinks and grabs ahold of the needle mechanism.

 

My tach kinda jumps around a little. I have mechanical secondaries, and everytime I get on it, the tach jumps up about 500 RPMs more than the engine really is doing, then comes back...Its just kind of weird. So if Im cruising at 3,500 RPMs in 3rd, then just floor it, the tach will jump to 4,000-4,200 RPMs, then come down to 3,700 or whatever the engine has worked its way up to by the time it comes back down. Could this be because of the sudden gulp of air that makes the engine hesitate and "die" for a split second? I have some spare ignitors, Im just too lazy to swap them out .

~T.J.

 

Ive got the same prob in the morning.....I just bought a new Autometer tach.....Im gonna put it in when I get the time