My prob is that my car runs great then out of no where wants to die. feels like it is starving for fuel but has new fuel system. when i get to about 2,000 rpms on the freeway it starts to kick and spudder then will start going again once i get over 2,000 rpms. sometime at stop signs it will die when i hit the gas then sometime it acks like it is going to die then picks back up. then sometime it does nothing. i thought it was mass air flow sensor but it check out fine. what do you think it is???