Information on my wiring setup
Tachometer (RPM Rev Counter)
Original setup
Originally the rpm signal is feed from the coil (-) (Single coil distributor) to the fuse box where the signal is distributed to the fuel pump relay, multi function instrument (shift light for economic driving, fuel consumption calculations) and tachometer.
New setup:
I'm now using 4 COPS and need a new tachometer signal and rpm signal to the fuel pump relay.
A possible solution is to wire signal from each coil with separation diodes into the cars original wiring
Using 4 high-voltage diodes (such as ES2J or BY399 or even 1n4007) to make a tach signal compatible with the original sounds good.
A similar solution is described at the bottom of this page http://www.megasquirt.info/ms2/EDIS.htm
Questions from others:
Why don't you control the shift light and fuel pump relay directly from the ECM ? To keep it simple I prefer to use a well known solution at the moment (and it's simple to wire in one cable)
More info will come shortly