Sprry to say this wont stop your engine starting up / It will start with out the conection on the back end of the iac . I would look for bad earth wire in and around engine . Do you do a fuel pressure test ?.Another thing is the IAC gets part message from the engine temp sensor and the OVP relay .Did you get fuel to the injectors ? Can you check the fuses on top of the OVP relay. The OVP is used to fire up the IAC