iv been through the pin outs on the ecu but i cant work out wich pin goes to the coil (wich was a light blue wire from memory) i want to find this wire to make as a kill switch if i have to il go to the coil but rather not closet thing i can find is the POST pin

look for the either PIP or SPOUT wire and ground it through your switch, they go from the ecu to the TFI module, not to the coil directly

break the circuit that pulls the ECU relay in

As mentioned the coil isn't controlled from the PCM... It is controlled from the TFI directly... Along with breaking the PIP or SPOUT signal you can break the fuel pump trigger, the power out to the injectors, or one of many other wires to immobilise the car...

Cheers,
Tim

As mentioned by TimmyA the negative pulse wire for the coil goes direct to the TFI module in the distributor (pink/blue)

it is easier to run one side of switch to earth and then run wire out to ECU relay (closes to engine behind battery - unless they have been moved )disconnect original earth to this relay that operates the pull in winding and connect your wire to operate the relay - you also wont get any fault codes as the ECU is not powered unless your switch is on........

yeah i found them i just wasnt sure if it was safe to cut them n add a switch or not