Tach signal w/o ECU

[Gimpin]

I am getting ready to set up my Autronic but the SMC model doesnt come with tach out put. Is there anyway I can wire in the tach so that I dont need the factory ECU or an MSD box of sorts?

 

[toybreaker]

Dan, I *believe* the tach and ecu share the tach signal.

(As in the ecu doesn't "make" the tach signal.)

This means you may be good to go as is...

Just hook up your new ecu/icemaker/ronco matic engine management system, leave the car harness alone and see what happens.






Caveat Wrencher If you let any magic smoke out trying this, I'm a gonna delete this post and pretend I'm still out on the road, somewhere where there's no intraweb... /ubbthreads/images/graemlins/arriba.gif

/ubbthreads/images/graemlins/grin.gif

 

[grocery_getter]

If you are using a 91-94 coil pack and transistor package, the tach signal can be sourced from the transistor pin out. There is a pin that is labeled "tach" on it.

If you are using 90 coil pack and transistor package, the tach signal can be sourced out of the little 3 prong 1" by 1" black box attached to the coil pack bracket.

 

[Gimpin]

thanks ... great info guys

next question ... do you know if these cars use "smart coils"

 

[grocery_getter]

No, these aren't smart coils, that's why we have to run a separate transistor/igniter setup on stock coil.