MSefi.com read only forum (Jan.15,2018)

What type of wire do I use to send an RPM signal to an MS2?

What terminal on the HEI?

What Pin # on the DB37?

What setings do I use in Tuner Studio?

I do not want to control the spark timing just tell MS how fast the engine is spinning.

Should be simple but I cannot find the answer on the forums or in the manual.

I have a 3.57 board.

Thanks.

Bzltyr,

Use the tach terminal (this is the same as using the coil negative terminal). On a four in module, this is pin 'C' (it is embossed on the module itself) which is also connected to the 'tach' terminal on the distributor cap. You connect that pin of the module to your MegaSquirt DB37 connector's pin #24.

Then set your number of cylinders in the software. Don't set anything for the missing tooth configuration, just leave it at the defaults. Then you will be ready to run.

There is more info on triggering when not controlling ignition here: http://www.megamanual.com/v22manual/mwire.htm#ignition

Lance.

Thank you Lance. Just any wire or a shielded wire? Ground the shileding?

Bzltyr,

I have run the 4-pin HEI (on a small block Chevy) as well as various 7-pin modules and I never found it necessary to shield the tach wire.

Lance.

Thanks again. I will give it a shot.