The complete automotive resource for buyers, sellers, and owners like you.
Car, Truck and SUV Forums at Roadfly
+ Bentley Forums
+ BMW Forums
+ Cadillac Forums
+ Chevrolet Forums
+ Ferrari Forums
+ Jaguar Forums
+ Lamborghini Forums
+ Lotus Forums
+ Mercedes-Benz Forums
+ Maserati Forums
+ MINI Forums
+ Porsche Forums
+ General Discussion
+ Marketplace Forums
Thanks Shawn... (archive)
[ Follow Ups ] [ Z3 Message Board ] [ Msg. Board FAQ ]
Posted by 1 Tuf Z3 on January 22, 2001 at 19:31:05:

In Reply to: Re: Source for tach hookup...not BMW... posted by Shawn Fogg on January 22, 2001 at 09:51:55:

Dealer gave me a diagram and suggested I tap into a wire under the dash...apparently a feed for tach equipped cars.

"It has 2 coils that fire 4 plugs. I hooked the ignition source wire up to one of the coils but the tach seems to be
registering about half of what it sould be. (5000 only showing 2500 etc). Does ANYONE have any idea
the source on this type of ignition system?"

I assume you are hooked into the negative side of one coil? Can you set the tach for a 2 cylinder engine? If so that should work for you. When each coil fires does it spark both plugs?

If you can't set the tach for a 2 cylinder you *might* be able to tie both negative coil leads together and run that to the tach. To do this you must isolate each from the other with diodes or you will end up triggering both coils (and all four plugs) on every spark which would be bad.

Also do you have a wiring diagram for the car? The DME might have a tach output you could just tap into.

Shawn




Follow Ups:


[ Follow Ups ] [ Z3 Message Board ] [ Msg. Board FAQ ]
Questions, comments, or problems, please visit the Roadfly help desk.
Roadfly.com Logo © 1997 - 2009 Jump Internet Inc. All rights reserved.