1995 Toyota 4Runner engine not running right

my 4runner will idle ok but under accelaration it would hesitate if i let of the gas a little bit it would catch up. i notice a loss in power really notice it if going up hill. i already have done complete tune up. i replaced the coil. still no change. so i replaced the vane airflow sensor. now my car idles good but when you give it gas it sounds like its not getting enough gas. if i push the gas pedal real slow it will rev to about 2000 rpm then cut out not die though. if i bring it to almost before it cuts out and hold it the engine surges. since i replaced airflow sensor i cant even drive it. help