i tried to search but its down, so please bear with me. anyways, i just installed a cluster with a tach in my dx. everything works but the tach is all jumping around. if i dont give it any gas it will stay at around 6-700. but when i give it some gas the needle will jump around, up to 4k and back down to about 2k. no... its not my engine. so did i buy a mess up cluster???

 

Who'd you buy it from? Awhile back, my DX Cluster in my old car had this problem with the spedomoter. I hit the needle wrong with my white face guages while installing them, and **** was never the same. I'd try to buy a new tach, or put your old **** back in.
You can get a brand new tach at http://www.slhondaparts.com under the exhaust electrical section.

Another possibility is a short...but I doubt it. You may have bought a bad Tach. Who'd you buy it from?