starts, runs for a few seconds

99 cavalier, its my sons car. car ran fine until this morning. no trouble or warning with this problem. starts, but it idles a little rough and stalls. starts again but even with fethering the gas pedal it won't run. it still stalls. The gas pedal is even hard to push. already had installed new plugs and replaced the pos battery cable to the starter. that was seperate issue. When I turn the key on I can hear the fuel injectors pre-load with fuel, it starts then stalls. fuel filter or a fuel sensor. Can't get it to run to have a code meter diagnostic. Any help is appreciated.

Duh on this newbies post, my son was out of town and did not tell me his gas gauge was broken. it was reading full, yet he knew it was almost out of gas and when parked down hill the pick up tube was dry. He put more gas in and it is fine now. I thank you in advanced if anyone was going to respond to my question. this was one of two cars I have issues with this weekend.

Thanks again. jd