Fuel presure only goes to 40 psi

Fuel pressure should be 57-73 psi engine running. Check your fuel filter, but kind of sounds like pump is bad.

When you replace the fuel pump I hope you are changieng the filter as well. If this is the case then look into the filter in the tank before pump pickup may be clogged or just not good. You could also have a linepartially blocked, not allowing it to go on. Also looking on the ford site, they show a thing similar to this due to a lower fuel level an dusing winter blend fuels. Which doesn't explainmuch except mean when your tank may be 1/4 or less then don't let it get that low in winter. Part of the problem is the stuff they put in for winter and unseasonably warm weather being the cause. Putting in higher octane does not help.