87 maxima

last week I was on my way home from work, the car was running great. I was at a stop sign, When I hit the gas the car sputtered and would not go over

35mph. I made it about three miles after that and the car quit. It is getting fire but it would not restart. I got the car towed home. The next day the car would start and only run 10-15 seconds and then it would die. I turned the key off and then back on to let the fuel pump cycle and the car would start back up and it would still only run for 10-15 seconds. I thought it was the fuel filter, I changed that and the car still won't run. I got a fuel pressure gauge and with the key on and the car not running it shows 30psi. With the motor started and what little time it will run, the pressure drops to 28psi. just before the car dies, the pressure goes up to 32-33psi. Is the fuel pump bad? If not what could it be? If the acclerator is pumped the car will keep running but it will barley run. I was told it could be the Mass air flow sensor, I unplugged that and the car still dies. Any suggestions on what the problem might be will be greatly appreciated.