Ford Repair Questions? Ask a Mechanic for Answers ASAP
Check the fuel pressure. Verify the proper pressure, engine running and that the pressure holds after the fuel pump stops running. Try to verify that the pressure is correct when it is hard to start. Proper fuel pressure is 30-35 PSI at idle and 40-45 PSI with no vacuum to the fuel pressure regulator. You can find the little port looks like a tire pressure gauge right on the fuel rail. I will try to find a image.
I suspect your fuel pump is bad even know you just replaced it or the fuel filter fuel lines have a blockage. If the pressure is within spec clean the MAF and replace the Coolant temp sensor as they are common to cause very rich lean conditions that will make these issues occur.
In the picture it shows the fuel pressure regulator so you can remove vacuum to properly test the pressure. Below it the little nipple is the fuel test port that is where you will install the tester to verify pressure. This vehicle takes a smaller connector than the standard new testers but is available at the auto store for an additional fee.