NetHeads, Somebody on CorvAircraft mentioned that the EIS seems to bounce around a bit, maybe plus or minus 80 rpm, and changes rapidly from one reading to another. Mine does the same thing, and it's quite distracting. But I finally got the Tiny Tach to work correctly (no thanks to the manufacturer). I eventually concluded that outside interference from other plug wires was causing it to fluctuate between reading either twice, half, three times, or four times more than the rpm than the engine was actually turning (all within seconds of each other). It was useless.
The thing that finally fixed it was wrapping the connection (the red wire that's already wrapped around the chosen plug wire) with aluminum foil, and then grounding that "shield" to the engine block with a ring terminal on the other . All the sudden, the Tiny Tach is the model of a wonderful digital tach....as proven by a digital tachometer that I eventually bought because I certainly couldn't trust the EIS OR the Tiny Tach, and couldn't figure out which one was even in the ballpark. You have to be careful to make sure you don't ground the red pickup wire, so I insulated the end of it (with small diameter shrink tubing or electrical tape) before I did the shield wrapping. To clean things up, copper braid could be used, but it comes unraveled easily during the process, so I stuck with aluminum foil. I used shrink tubing to hold the whole mess together and give it a neat appearance. Since the fix, my Tiny Tach has become my primary tach. I say that because it only updates about once every second or two, and it seems to average the readings so that fluctuations are minimal (in line with the optical tach that I bought). The EIS bounces around so much as to be distracting and difficult to read, the kind of thing that gives digital instruments a bad name versus analog. I guess I should talk to them about that. At the KR Gathering in September Jim Faughn approached me regarding his Tiny Tach, which had acted just like mine, just plain haywire. We were both busy but I gave him the 10 second version of "the fix", which he applied the next morning after finagling some aluminum foil from somewhere. Later in the day he gave me the thumbs up and said it was fixed. The interesting thing about this is that he's using Moroso Blue Max spiral wound sparkplug wires, like mine. The TT seems to be confused by sprial wound wires, but at least now I have a workaround... Mark Langford, Huntsville, Alabama N56ML "at" hiwaay.net see KR2S project at http://home.hiwaay.net/~langford
