1999 29 Outlaw with a single 454 mag Mpi. last year the tach would bounce a bit and after a few miles, it would stabilize. This year, I fired up for first time out and it is dead and staying at 600 rpm's. I am guessing a shot tach or a ground issue. Question is, anyone know where the tach grounds to for me to check? Is there an "easy" voltage check I can do under the dash panel or a way to jump across the signal to see if the tach itself is truly junk at this point?

edit. I hate spell check. My tach is not dieting. Dying maybe, but not dieting. Can't edit header.

My tach is dead after the winter slumber and spent hours chasing wires, calling the ignition manufacturer, etc until I just said fuggit. And then after a day or two of use it came back alive. Go figure. I think 20 years is a good run for a set of gauges and plan on redoing mine over next winter. I have '97 Islander 272.

Sometimes if you turn the Cyl# switch (on the back of tach) back and forth a bunch of times they ill come back. Make sure you put it back on the same cyl # position it originally was. There are set up for 4cyl's, 6 cyl's, and 8 cyl's.

Obviously make sure the wires to it are clean and connected cleanly.