Sounds like low it to me. Check the fuel line pressure, replace the pump if necessary.
If you've replaced the filter (properly?) and blown out the hoses, it's low pressure. And low pressure can be caused by a faulty pump or clog somewhere in the system. check to see if there is a screen in the fuel tank, sometimes that can get clogged or gummy. Also check if your fuel is alright. Did it get gummed up and contaminated?
Thomas Falater