RPM gauge is off by 200 rpms

[ProwlerGT]

My RPM gauge in the dash is off by about 200 RPMs. What would/could cause this? How do the RPMs get relayed to the RPM gauge? I have a 1995 NA Hybrid, but I'll settle for any answer so I can understand how RPMs are sent to the gauge from other cars' engines too.

I have not taken the gauges apart. I did tighten a screw on my ignition switch which required removing the steering collar/cover and underdash "knee protector". Any other work I've done recently I cannot see how it would affect RPMs being reported incorrectly. I've installed a rebuilt TB, bored out 3 more mm, the TB shaft has been machined to fit turbo shaft seals, installed a new working IAC, configured/tested the TPS, adjusted the throttle cable tension while the datalogger was on, replaced the whole brake system, replaced nearly all suspension parts including new shocks/struts/links/ball joints, etc.. Ugg I don't know what work would've caused this problem to pop up and I don't know if any work did cause it, but its aggravating. I'm using my senses and the datalogger to discern that the RPM gauge in the car dash is wrong btw - logger says right idle RPMs and it sounds/feels right too, but dash says its like 850 - 900 whereas logger says from 688 - 750.

[Highboosted]

Probly either a problem with the hybrid logger or all cars are like that. The hybrid logger (shiver's) will tell you a lower idle RPM than what the gauge says on all cars. It seems on target when the RPMS are higher, but at idle something's off (most likely the logger, since everyone has the same problem).

[ProwlerGT]

Originally Posted by Highboosted

Probly either a problem with the hybrid logger or all cars are like that. The hybrid logger (shiver's) will tell you a lower idle RPM than what the gauge says on all cars. It seems on target when the RPMS are higher, but at idle something's off (most likely the logger, since everyone has the same problem).

So which one do I trust for correct RPMs?

And again what is it that give the dashboard the RPM reading? Is this just the Crankshaft or Camshaft position sensor?

[Highboosted]

Trust the gauge, shivers logger has had this problem for a while as far as I know (and it was confirmed in your other thread).

RPM comes from the ECU via crankshaft sensor on 2G cars.

[ProwlerGT]

Originally Posted by Highboosted

Trust the gauge, shivers logger has had this problem for a while as far as I know (and it was confirmed in your other thread).

RPM comes from the ECU via crankshaft sensor on 2G cars.

Thanks man. I'd wanted to get a tachometer (expensive it seems unless I don't know where to look) and see what it would say and compare to the logger and gauge, but I'd rather not spend any more cash right now. I don't know why I didn't think of the crankshaft sensor earlier. Perhaps its cause its infrequently visited.