'93 Sunbird tach question

[tomrhere]

Yep, me again...

Car is running great. I just have a curiousity question about the tach.

What gives the tach it's signal as to engine rpm?

Reason for asking is the tach in this car is just plain whacko, on drugs I think.

For a refresher, it's a '93 Pontiac Sunbird SE, 3.1L MPFI, Auto.

Issue is, the tach will read all over the place, even though you can't hear any change in engine rpm. Running at a steady speed down the road, rpm's indicated will jump 200 to 1000+ with no change in actual speed or rpm's as the ears and eyes can tell. No effect to speed when using the cruise either, don't think there's an actual issue here otherwise.

Basically just curious is all. If I can remedy the situation easily, I will, but I ain't none to worried about it. Wife ain't either. Bonus!!!!!!

[FIREDOG]

your tach receives it signal from the crank sensor.

see: <!-- m --><a class="postlink" href="http://www.autozone.com/addVehicleId,1913302/initialAction,repairGuide/shopping/repairGuide.htm?pageId=0900c1528003bb4b">http://www.autozone.com/addVehicleId,19 ... 528003bb4b</a><!-- m -->

[tomrhere]

Thanks....