Crazy Tachometer Readings Nov 3, 2010 10:15:32 GMT -5 Quote Select PostDeselect PostLink to PostMemberGive GiftBack to Top Post by Lucid on Nov 3, 2010 10:15:32 GMT -5 My IROC has been getting weird RPM readings ever since I got the car. It has always seemed to rev up really high in the readings but now its gotten a lot worse. The tach says the engine idles at 2500 RPM. I found this thread on thirdgen.org:www.thirdgen.org/techboard/electronics/279765-tachometer-waaaaayyy-off.htmlThere apparently is a capacitor and resistor on the tach board that go out and need to be replaced for it to read correctly. Before I try to fix it though, I want to get a spare unit as a back up. Here is another thread for the 90-92 drivers:www.thirdgen.org/techboard/electronics/357893-90-92-tachometer-fix.html?