2015 tundra cold start issue. DRIVING ME NUTS.

I have a 2015 tundra TRD pro 5.7 flex. I only have an issue when the truck sits for a half a day or over night. It will have trouble starting and idle rough for a few second then after that I can shut it off and start it back up with no issues. Once it does start up it blows a little smoke and smells like fuel.

I’ve changed the fuel pump, fuel pump ecm, battery, coolant temp sensor. Are you supposed to have it remapped after changing the fuel pump? Is that my issue?

also it’s been doing this for over a year and has only thrown one code ever (lean on bank 1 and 2) !

 

The flex fuel issue is supposedly remedied by changing the fuel pump (Toyota recommends, but many don’t report any improvement) and by resetting / updating the ECU. The reset process is convoluted and has to be followed to the T. Many do not follow the instructions properly and also report no improvement. Some have simply bought an aftermarket computer scanner tool that can read and reset the ALC%. Those have reported the symptoms resolving.

 

Give this thread a read:
https://www.tundras.com/threads/alcohol-density-fuel-trim-issues.45180/