My husband says; could be a bad fuel pump(so good thing you got that), or clogged filter(make sure you can blow through it without much restriction)...if it's fuel injected then the computer could be going out, or the fuel injectors are clogged. He says to get two bottles of Prestone carburetor&fuel injection cleaner, and get a cheap little spray bottle...need one person to try and start the car while somebody sprays the spray bottle filled with the cleaner into the throttle body or carburetor. If it's dirty or clogged fuel injectors, spraying that stuff directly into the air-intake will clean the fuel injectors and the valves(even faster than what it would do running from the tank). Put one bottle of cleaner into the tank and use the other bottle to spray into the air-intake until the entire bottle is gone.With the Prestone cleaner you should see an improvement.Good Luck...