Sounds like it could be a few things actually. If the engine is not idling correctly and you are having to press the accelerator to have it run then it could be the BAC(Bypass Air Control)valve located right below the intake manifold next to the top fuel rail. Disconnect the harness from that and try to crank the car. Could also be bad TPS sensor or MAF(mass airflow) sensor giving bad readouts. Had that issue before.