Mystery Stalling! Need help

Hi there
I need a brilliant mind to help me solve this issue before I have to send the old boy for retirement!
2008 Tundra 5.7l
When I start him on cold or damp days it turns over, runs for 2 or 3 seconds then stalls out. It also starts on a very high idle when this occurs. No code is thrown when this happens and I have changed the mass air flow sensor twice. Dealers can't find an issue and neither can anyone else. Please help

 

First thing that pops into my head is a fueling issue.

Fuel, air, spark. Does it have and maintain fuel pressure during the cranking? It probably is getting air and compression. And if it starts for a second probably has spark.

If it starts for a moment then chokes out that seems like a fuel flow issue usually in my experience, and that wouldn't throw a code either.

 

OEM MAF sensor replacement? Toyotas are electronic sensitive. Aftermarket brands don’t play in the same specs. Unusual idle screams of air fuel metering issue or vacuum line problem. If you start it, can you use the gas pedal to keep it running?

 

Sensor was replaced with a toyota part, both from the dealer. I cannot keep it running with the throttle either.

 

Fuel pump ECU and fuel pump should be checked. And actually there was a post here just yesterday with a video of a 2020 with similar issue. Dealer could not fix or replicate, independent shop did a vid of diagnosis and fix. Fuel pump was seizing intermittently.

Try banging the gas tank with a plastic hammer, see if that frees up the pump for it to start. Wont fix your issue, but if it starts and runs after doing that for a little bit then you will know the pump is seizing.

 

I have a similar situation with my 2012. Mine only misbehaves below 20 Degrees... it starts, roars to life and then immediately shuts down. I found that if I heat the interior through the passenger door with a propane torpedo heater it takes 5 minutes until it starts and runs fine. Still trying to figure it out but mine may be the ecu. And yes, had it to Toyota and they found nothing wrong in their heated garage.

 

I thought it might be the Idol Air Control valve. I recently bought myself a code reader and plan to use it when it happens at home, since it never does it anywhere else. It never stores the code, but I'm curious if it will have one the moment it happens.