Why wont my car stay running

My car died on me after lossing power. Now it will start run for a min mabey then instently die. After words it will start but die imedetly without even running for a second. I have checked all the sensors and the computer tested the ignition coils repetedly and the ignition control modual. I get spark but it is very week and after attaching a presure gage I am holding fule presure. Plz help I am very frustrated and in need of my car.