I noticed a few weeks ago that when I would go to 80%-W.O.T., it seemed as if the tachometer couldn't keep up. The needle was jumping in ~750rpm increments instead of having a steedy sweep. My first guess was a faulty Crankshaft Position Sensor.

Then today I noticed something that I really did not like. I was crusing a steady 60mph on the highway, and looked down and the tachometer needle was jumping up ~500rpms sparatically, and no change in the throttle position. Once again, sounds like a Crankshaft Position Sensor to me.

Has anybody had this or a similar problem? Any input or advice I'd greatly appreciate. Thanks.

 

have you recently replaced the needles? (to maybe paint them yellow or something..) because my friends tach was jumpy like that after taking his off to paint them

 

Tach needle has not been touched.

 

VSS...crankshaft has nothing to do w/ tach, only timing.

If not faulty gauge, check the connection or replace if needed.

 

Are you saying that it could be the VSS?

 

I had the same problem with my civic. I thought it was the vss, but it ended up being the connector itself. The pins were corroded a little and seemed alittle loose in the plug, so i cut it off and put a new one up there and havent had a problem since.

 

The connector to the Vehicle Speed Sensor?

 

???

 

I was driving down the road one day.. rpms started jumping.. car started running horrible.. car died.. no spark.. test ICM.. had to replace my ignitor..

A jumpy tach could be a few things.. it could be a possible bad ICM (ignition control module) AKA the ignitor .. You can pull the distributor cap and inspect the connections to the coil and ignitor.. possibly put a tad bit of electrical grease.. if you have a voltimeter you can test them.

 

Icm x39572949021

 

Yes the vss connector

 

Yes

 

This is something I'll look into, but the car isn't running rough at all. No changing in how the motor runs. Does that rule this out?

I will check that sometime soon. Is that located in the transmission?