Engine turns over but will not start unless u hold the gas, on 1995 Mazda Protege

changed filter screen on fuel pump,new fuel filter,new distributor cap and rotor,new wires and plugs,at my wits end also voltage regulator replaced,please help

1 answer 1 comment
Clean the mass airflow sensor.
Thank U so much,is this the only thing that could cause it to act like this.