Does it start and then shut off or not try to start at all??
If it starts and then shuts off it could be that the engine immobilizer is shutting it down.

 

It starts then shuts off, but only when I spray starting fluid in the intake. Otherwise it just cranks.

Not sure why the immobilizer would be activated. I took the truck to get some fast food two nights before it stopped starting, no accidents, no crazy driving.

Also, there's no light that pops up on the dash to show the key is bad or anything

 

Definitely sounds like you're not getting fuel for some reason. You need to test the fuel pressure. Fuel pump maybe running just not producing enough pressure to fuel the system.

 

Your gas gauge is broken.

 

Tore the tank out of the truck to do some investigation. DEFINITELY not a broken gauge. It has a quarter tank in it . Have a better reader too. Immobilizer not engaged

When I check voltage at the plug that ran into the fuel pump I’m getting about 10.4 volts with key on. When cranking it shows 12.3 so it seems like everything up to the pump is good.

Here’s a video of the pump hooked up. This seem like 40psi?
https://youtu.be/roLQ1UyLYvI

 

No it doesn't

 

Because I hate to see car problem threads go un-updated, it turns out (so far) that it was the Fuel Pump ECU. I'm not sure if it's Flex Fuel specific or Sequoia specific or year or what, but all of the diagrams showing the location of the fuel pump ECU online are incorrect (that I could find). I so thankfully had a friend who works the parts counter at Toyota check with a tech friend of his and he quickly knew it was under the spare, but somehow he was the only tech in this entire dealership that had ever seen one because everyone else thought it was somewhere else.

notes:

- Fuel pumps on Tundras and Sequoias apparently don't prime in the traditional sense
- Get an advanced scanner to check the codes, little $20 jobs won't read as deep as you need them to (Thanks Toyota)
- There's no way to test the ECU (Thanks Toyota), the tech manual just says "replace" if you get to that point in the troubleshooting guide. So since that's where I was, that's what I did. It fired up immediately and I've driven it around town and to work and it's doing well, 18mpg even.