early m20 fitted to late car what wire do i join to make rev

[s9jja]

hi there all got my car up and running its a early hi comp engine and the car is a late one. does anyone know what wire i need to join from the ecu the white plug to where and what colour wires?????????

[evilming318ia]

There should be a 3 pin plug near the ecu you must connect one of them to a back cable in the rev count in order to make it work did this on mine and it worked must have a look in the car to figure out what color it is in the 3 pin connector