Hi guys, strange problem that shops here don't want to seem to troubleshoot. Recently I just replaced my fuel pump. Now when it is over 105 degrees out, the engine sputters and chuggs. Guys are saying that fuel injected motors do not vapor lock, but I'm guessing something is going wrong along those lines. Any suggestions? I did not put in a fuel pump from the dealer, maybe that is my first step? I don't want to get rid of the truck but I'm getting frustrated. Appreciate your help guys.

2001 Ford F-150 5.4 2wd

_brian