01 Sunfire Won't Start

01 Sunfire won't start, it just turns over. It has been doing this for about 6 months. The first time it happened it had about a 1/4 of gas in it. I disconnect the fuel filter and turned the car over to see if it was pumping fuel and it was not. I hooked it back up and waited til the weekend to fix it thinking the fuel pump had gone out. The weekend came and it still didn't start so i jacked up the rear of the car and started to disconnect the lines. The fuel line was pressurized so i hooked it back up and it started and ran great. I dropped the car and drove it for sometime. It has happened a few more times since then, and each time the car was above 1/4 of a tank and had as much as 1/2 a tank of gas. We figured out that if we add a few gallons of gas it will start up and run fine. It just started doing it again and I want to fix it this time. I dropped the tank and pulled the pump. I inspected it and the tank for any debris that may be causing a blockage but everything looked fine. I hooked everything back up and it still won't start. I don't want to replace the pump unless it is absolutely necessary because if it is not that then it will be $250 down the drain. Anyone have any ideas?

Get your fuel pressure checked properly.....lol

My experience with fuel pumps is they either fail or work...and once they fail they seldom fix themselves. You didn't state whether you checked the flow before or after the fuel filter....When was the last time the fuel filter was replaced? I would check the pressure of the fuel line up in the engine compartment, at the connection where it hooks into the fuel rail. The injectors need a minimum line pressure in order to function properly. Since the pump is electric, you shouldn't have to turn the engine over to get it working, only turn the key to the point just prior to cranking the engine and see what you have...Do this when the engine is cold.