View Full Version : Bad tach

10-28-2002, 04:17 AM
Have any of you folks run across this..

My tach is reading way too high.. I would say about double what the motor is doing. The tach is new, and I'm wired for positive earth.

Any ideas? This read high from the word go after my rebuild was complete.. It didn't read normal then just jump to double... images/icons/confused.gif

10-28-2002, 10:45 AM
Is this on your Elan? If so, do you have an electronic ignition on it?

10-28-2002, 02:25 PM
Yes it's on the Elan.. It's running points..

10-28-2002, 02:41 PM
You're probably aware of the problems Elan tachs have with electronic ignitions and some accesories depending on how they're wired, as well as the solutions. (If not, you can start at:
https://www.lotuselan.net/publish/bouncing_tach.shtml )

Is it possible the tach was altered at some point?

I think I have some material in hardcopy that I could look up and scan if you need it - mostly stuff that Lotus Ltd. has published over the years. Let me know & I'll look.

10-29-2002, 04:48 AM
I do have an electric fuel pump, but it gets its power off of a pressure switch plumbed into my oil line, and grounds directly to the battery ( positive earth ) this cuts the fuel pump off when the oil pressure drops below 20 PSI. The tach is brand new and should be unmolested..

Maybe I will try my old tach to see if there is any difference..