slinky25

My tachometer is going crazy very often, sometimes its just completed pegged out and sometimes it just moves all over the place, it never shows a steady idle although the car runs just fine. I am certain its the sensor but I have no idea where it is located. Can you please explain to me where to find it or give input if you think it is something else causing this problem.

Thanks for the info and the link, there is 1 under the hood and 1 on the exhaust, but today I removed the ignition coils and the spark plugs, did a very thorough cleaning and took careful time to replace everything, so far it is running very solid pretty much just as well as when i bought it 2 years ago (it hasn't ran that good in over a year) so hopefully the problem will not persist. I'm not that savvy with how everything works but mechanically i don't have a problem with replacing parts and configuring everything, so the input is definitely appreciated. Thanks again.

My skyline has been idling rough for a little over a year, I have a 97 GTS25t R33. What is does is when I am idle or accelerating quickly it will bog down a little or misfire, it's very noticeable and sometimes it is more frequent than others. It is much more noticeable when I am running the A/C also. It helps when I put the car in neutral at a stop light but still does it a little bit, when I am at cruising speeds it seems to be just fine although I think it would be harder to notice at those speeds, but definitely the worst when I acceleration especially going up hills. I have replace the spark plugs first and that seemed to make it better for just a couple of days. I changed both oxygen sensors, and recently just thoroughly cleaned the MAF sensor. I am looking towards the injectors next but would like some input before I dig into such a large job. Like I said it has been about the same for a little over a year, not really getting worse, but bad enough on a daily basis and more so when I run the A/C. Any help would be greatly appreciated.