1989 ford escort pony

I have a 1989 ford escort pony I can get it to crank up but once I let go of the key it will shut right back off and when the key turned to on I do not hear the fuel pump only time I hear my fuel pump is if I crank the car up and my gas gauge is not working either I have changed the diafram and spark plugs distributer cap wires checked the fuses what could it be ?