Hesitating starting issue

I have a 2017 limited edition tundra. It started struggling to start and would crank for a long period of time before starting. It doesn’t do it all the time only when it’s really hot or really cold out and only after leaving it sit more then 4 hours. After reading some post i have replaced and done the following:
New battery
Fuel system treatment
New fuel pump
Had Toyota dealership reflash the cmu
I’m really at a lose about what else the issue could be. Any help would be appreciated

 

Do you have access to a scan tool, Could look at the fuel alcohol level, if it s high, could cause the problems you Describe, other best guess is that your fuel pump isn't holding pressure and allowing the pressure in the line to bleed off, causing a long crank time. In that case, new fuel pump

 

I don’t have access to a scan tool. I did drop the fuel tank and put a new fuel pump in. It seemed to fix the issue for the last three months and now it started doing it again

 

There was a TSB issued a while back for extended crank issues. It boils down to the ethanol sensors needing to be reset and updated. Any Dealership should be able to handle it.

 

Could be as simple as a loose or disconnected vacuum hose.

 

I did do the tsb update. No luck

 

Are you losing Fuel pressure, Should be a Schrader valve somewhere on the fuel rail, easy to check, probably should be around 25-30 psi before you even crank the engine

 

My 2015 flex started hesitating at initial start. Not too bad but very noticeable.
I started reading this thread and tried switching to a non-ethanol fuel.
It worked....2 tanks later and it was completely gone. Just thought I'd pass this along.