does the car run above idle when u hold it constantly at say 3000rpm or does it just act the same as on idle and stalls and when it stalls is just a straight cut or does it stumble or starve like its not getting fuel. Could be fuel pump if it starves but if it just stalls it most likely a sensor, have you checked the crank angle sensor at all, wiring/plug etc, if thats not right there's no fuel or spark and instant stall.