Help- Tundra randomly cuts out.

I own a 2007 Tundra 4.7 V-8 with 102k miles.

I joined this forum in hopes of getting some help/advise. Recently, my truck has been cutting out without any warning. At first this would only happen at idle, and most recently happed while driving. When it dies, 90% it will fire right back up without an issue. Other times i have to wait about 5 minutes before it will crank over. No Check engine light, not are there any stored codes. Things I’ve done to mitigate the issue are as follows:

Replaced air filter
Replaced mass air flow sensor (just to be on the safe side).
Cleaned the throttle body.
Tested the alternator- seems fine
Tested the fuel pump-seems fine.
Took it to my local Toyota dealership to see if they could figure it ou- they spent 4 hrs with no avail. Only thing they noticed was right before it died was the voltage slightly dropped. They said “we think it’s the alternator but cannot guarantee. If you would like further diagnostics, it’ll be $160 per hr.”

Any tips or recommendations on addressing the issue?

 

I’d start by checking all your grounds.

 

How old is your battery? Has your battery ever been drained IE left a light on? If it’s old…this heat wave could be causing problems.

 

Battery is brand new. That is something else I replace for safe measure.

 

Voltage drops before dying? Well are the battery terminal's 100% clean?
Is the ground wire from bat to fender good and have a good ground (probe fender near ground and battery negative is the resistance.5 ohlms or lower).
Are the contacts clean on the wire that comes from the alternator to positive side of the battery?
Are the contacts good on the wire on the back side of alternator?
Is the nut loose on the back of the alternator?
Are all the engine grounds clean an not cut or corroded?
When it is running before it cuts out does the alternator have ticking or grinding sound from it?
Prob the ignition relay does it stay closed the whole time or does it fall open?
Is the battery staying charged or is it losing amps?
Are there aftermarket accessories that have been installed recently around time of the problem?
Or just in the past?

a real scan tool is something thats really needed , It could be data logging alot of things and every sensor and a skill tech who can read through it and down to the common shared circuit or path could figure it pretty quick.

also the alternator is probably the culprit cause of the voltage regulator, but really can't do diagnostic's over the internet with such little information for a electrical issue , can sorta point you in the direction or a path

 

Swap out your battety with the warranty... sometimes new batteries are also old, theyve probably sat on some lot then some more on a shelf, so odds are your new battery is 2 years old... mine use to cut out while driving too.. would start up and die later on.. it was super random... went through a dozen OEM batteries before the switch to Optima...

 

any after market alarm???