Odd Tachometer Issue.

[BigDAT]

I searched around the internet a bit, but couldn't find any real help on this Topic.
Let me describe it the best I can..

Car is off, tach reads 0.
Start car, at idle tach reads 3k
While accelerating, the tach stays at 3k until you reach a certain RPM (Unknown)
Once you reach this RPM the tach starts moving in REVERSE! 3k-0
The car redlines at 0RPM


Any ideas? Checked the connection to the ECU and the CAS, cleaned and greased both of them, no help.

Any ideas?

[skywhine]

Possible issue with the tach itself. It has an electronic motor in the cluster that operates it. i know 240's have an issue with the speedo motor in the cluster going bad and doing all kinds of crazy things like giong backwards..always showing 70mph, or not working at all. The fix is to replace the cluster (Or just the speedometer assembly inside the cluster if you are mechanically inclined). I would say if its running just fine than the problem is between the ECU and the tach (Including the tach). If its running normal than its not a signal problem from the CAS as if it was it wouldn't run properly. Most likely is the tach itself i would say, however im not saying that IS your problem, just the most likely.

[t.mcginley.jr]

Does the car run normally?

[BigDAT]

Does the car run normally?

Originally I thought so, but it almost sounds like it has a misfire (lowish RPM) but its only prominent when I am not very hard on the throttle.

[Matt300ZXT]

I had absolutely no reading on my tachometer when I got the car. I took the cluster out one day and inspected the solder joints on the tach motor board itself and repaired it. Put it back in and voila....instant tach response. Email me if you want to try it yourself and want more info at [email protected]

[jchamber22]

BigDAT- were you able to get this fixed? I am having the exact same problem with my 92 TT.