Won't fire when gas below 1/2 tank

[randyibm]

I have a 2001 4 cyl. When I first got it 8 months ago I had this problem but it went away. It failed today and this is what I know.
My daughter called me and said car won't start.
I get there and find it turns over very well but no fire.
I turned the key to on and I could hear the pump run then shut off like it should. I then turned on the starter but no fire, except just 1 time. So I then turned the key off and on about 6 times without starter then when I started it it tried. I can tell at that point I had a fuel delivery problem. The tank was just below 1/2.
I suspected the fuel pump. I did not want to call for a wrecker so I first went and got 2.5 gal of gas and added it to the tank. It started right up! I took it to a garage and explained everything I knew and after 4 hours I went back to get my car before they totally screwed it up. Long story. So I would like to ask the experts out there what would cause the gas level in the tank to make a difference for fuel delivery. Also do you know where the filter is, or is it part of the pump? Thanks in advance for your help. Randy

[markm_04]

I believe the fuel filter is located very near the gas tank. Either directly behind or possibly above the tank. I wouldnt hurt to install a new fuel filter to see if that helps any of your fuel delivery problems, or just to know that you have a fresh filter too. Just a suggestion...

[Mirage]

could it be a stuck float? causing it to read at half tank even though its really empty? that would mean once you added the gas, it had gas again. if at empty sometimes the car will attempt to start then die out again due to lack of fuel. its a possibility. a clogged fuel filter can cause non starting problems if it gets REALLY bad.

[randyibm]

Thanks guys...... I did go fill it up today to see how much it would take thinking the same type thing and the gauge was correct The float was not stuck. But thanks.

[Nighthawk243]

Could be possible that it is not getting adequate fuel pressure when under 1/2 tank. Maybe having the extra fuel in there is providing enough pressure through gravity to make it work, but when it its 1/2 tank, it doesn't have enough.