I have searched on this and tried everything I could find to fix it. It flutters around and jumps about 100 or so RPMs constantly. It is running smooth. No interference on radio, checked battery connections, checked connections on coil/distributor, moved wires away from coil and alternator is putting out about 14.5. It has a 6 month old control module and plug wires. This just started a couple of days ago. What else could it be?

 

TTT

 

Now it appears that temp, oil, bat, and tach needles are all jumping just a little. Does this point to alternator?

 

If it was just the tach, I would say the IAC, or TPS.

You might want to check those just because... but it might just be a ground problem. Check the ground under the steering column too.

 

replace the plug wires, it fixed my tach bouncing

 

It's mostly the tach. I don't know if the others used to shake a little or not, but I know the tach didn't do this. I saw the temp gauge jump quite a bit a few times. I don't think it is the plug wires. They're new and I checked each of them for wear. I guess they could be junk though. There is no miss at all. Runs just as smooth as it ever did. TPS is new, but I'll check it anyway and see if I can locate the ground under the column. I'm going to pull out the gauge cluster and check the connections on that tomorrow. Any other suggestions? I'm all ears!

 

It sounds like power fluctuations. Check the volts at the battery with a DVM while the car is running. I dont think any of the gauges are compensated for changes in voltage. I know the temp gauge definatly isnt.

The other possibility is that the connection for the tach at the coil is getting staticy or the module is cutting out every once in a while. Thatll usually cause the motor to run flakey, though. Could even be a bum tach for that matter or a bad ground.

 

I'm going to check it now.

 

It goes from 14.3 to 14.4 over and over. I'm guessing that is not enough to cause the tach to jump. That small fluctuation doesn't appear to be in time with the tach flutter either.

 

replace th plug wires, go out and check the car in pitch black, if you see blue sparks jumping you know they are broken.