went to start up my 93 coupe today after it had been sitting for about a week. would turn over but would not start. i couldnot hear the fuel pump kicking on when i turned the ignition so im pretty sure that is it. so i go under the car and bop the fuel tank with rubber mallet. it took a few times but it finally started up. but while holding the gas pedal to the floor it would rev up and down between 3 and 4 rpm, finally it broke loose and jumped up to 7 rpm and then the car started up fine, but then when the car would idol it would barly be running. i can hardly hear it and it stays at about 400 rpm. is this my fuel pump going out or what?

 

anyone?