[N0DIH]

Check the evaporative emissions too.

Try removing the gas cap before you start and see if that fixes the problem. If there a misrouted or broken line in the evaporative emissions can cause strange issues.

Check fuel pressure when you know the condition will happen. I would have checked fuel pressure first before throwing the pump and relay into it. You can toss a lot of money away throwing parts at a problem. Almost everything is troubleshootable, don't guess. Make sure if you take it to a mechanic that they don't do the same thing (all too many do the same blowing hundreds if not thousands of your money just troubleshooting because they don't have a clue). Find a GOOD mech that you can trust if you are taking it to one. Dealers aren't perfect either.