Backstory of a problem that I never fixed but could be part of the problem I'm facing now. RV would randomly just die while driving. It. Happen once about 3 years ago and later happened once and then after that happened multiple times a day one day. Never thought anything about it after starting it right back up . That day, after always starting after parking and turning the key back on. I thought I fixed it by switching the fuses from the horn and the fuel pump. It's been running good for 2,000 mi.
Now jump forward to today...we came out of Walmart from grocery shopping and it would crank but would not start. It was running fine until this time. It just cranks and cranks and wants to start but it won't.
Here's what I've done in order.
Change the crank shaft positioning sensor
Change The camshaft positioning sensor
Banged on the bottom of the fuel tank while trying to start it
Listen for the fuel pump. See if we could hear it and we did
Switch the fuses in the fuse box with another fuse in place of the fuel pump relay
Took the fuel line off and turn the key to see if gas came out and it did
Change the fuel pump module on the back rail
Made sure the inertia switch was not tripped
Had Mobile Ford dealership mechanic plug in scanner and said no codes found

After all this I gave up and had a local repair shop tow it to their yard. They told me it was a bad fuel pump and I was kind of relieved but very skeptical at the same time. I asked him how they knew that and he said they checked the pressure and it was low. I was feeling better. I okayed them to change the fuel pump. Went back a week later. They said they changed the fuel pump twice because it didn't fix the issue. But it did have the right of pressure that it needed of 60 PSI.
So this is where I'm posting this and I'm at a crossroads and not knowing if they're actually doing any research into this or if they're just throwing the parts Cannon at it. Thought I would come here and ask if there's anybody here that has any suggestions that we haven't tried. I'm hoping the repair shop that I'm at actually goes in and tries to diagnose it with a multimeter and cancels things out instead of throwing parts at it, and that's why I'm posting here.
2005 Ford triton V10 Gas
Please see video below

https://youtu.be/4zfc15L4yvc?si=D3PiBJCObBOUvLW2

 

Did you check the AIC valve?

 

Agree on the IAC valve.

Is there spark?

Does the exhaust smell like fuel while cranking?

Does the tach needle move while cranking?