1996 Buick Century engine starts runs then stalls

Engine starts runs then stalls problem has been progressive it began stalling every so often and predominately while vehicle was in motion I have replaced fuel filter used code reader replaced mass air flow sensor according to code on reader prob. Still exists next checked for fuel to throttle body or injectors start engine and sprayed either into air intake engine will stay running while either is supplied you can hear the fuel pump whirr! When the ign. Key is turned to the on position also while engine is running checked for fuel presure at schrader valve on fuel rail and with engine not running by means of depressing the valve with pocket screw driver just a trickle of fuel comes out it is my belief that there should be high pressure fuel comming out of that test port when the schrader valve is depressed also (note) rechecked with code reader and the code for a trouble maf sensor does not appear any longer iam a profesional appliance tech but iam affraid this is more complex to diagnose properly than a washing machine help my wife wants to get rid of the car it was her aunts and is almost in mint cond. I want to keep it as I know it is not a serios prob. Iam disabled and cannot afford to throw a good vehicle away for lack of patience or for me lack of expertise any help will be appreciated thank you! Frustrated wash machine mech.