If you haven't got 12V to ECU pin 20, check to see if you've got 12V to the injectors - as per wiring diagram in link above.

If there is 12V at the injectors, then the wire to pin 20 has a break/bad connection. If there isn't 12V at the injectors, then either the relay is knackered, or the wiring to it is knackered.

There should be 12V permanently to relay pin 30, and a switched 12V to relay pin 86, which in turn should give you 12V at ECU pin 10.