So I did the e fuel on my truck and when I'm running on the front take it takes about 10 sec to get up to 65psi but if I'm on my rear tank it comes up fine ...
There is a flapper valve about at the 1/8-1/4 level on the fuel pickup tube in case there is a blockage of the fuel pickup. Sometimes the flapper fails. You should pull the fuel sender/pickup assembly to check if the pickup has a blockage or the flapper valve is intact. The black plastic end on the fuel pickup is known to rot off also.