The tachometer was not working when I got the car, had an extra one from my 914 that I knew was good, did a temp hook up with the that and still nothing. Checked the output from the 912 coil verses my 914 and it was a lot lower which led me to suspect the mark ten ignition. Found online that they can be a problem for electronic tachometers but that there was a bypass switch on the Mark ten, when I switched it off the tachometer worked.

Is there a way to wire the tachometer to work with the Mark ten?

Should I just uninstall the Mark ten?

Is there something else that is better and will work with the tachometer?

 

Hmmmm. I have been successful with a drop in distributor from 123ignitionusa.com. The factory unit rebuilt by one of the on-line specialists is a great option too. But if you want the extra zap and no points then look to the 123. Absolutely no tach issues with those routes.

BTW, here is a thread that may be helpful:

http://forums.pelicanparts.com/porsc...-ignition.html