did you switch teh wires at the dissy?
what do you mean to the ecu directly? directly to what on the ecu?you need to supply power to all the injectors, you can use the power (positive/+12v) wires from your two original injectors and branch those two to all 4 of your new injectors. and then just wire up the negative side of the injector to your ecu directly, or figure out the harness.