Missing Fuel Trim

When I start the truck from cold lately I get a rough idle and significant loss of power.

I have noticed the short fuel trim on both banks will stay at zero. Long term fuel trim has readings however.

STFT will stay at zero with odd power issues, rough idle even after engine reaches operating temp.

However... if I turn off the ignition for just a couple seconds, STFT starts to track, power comes back and idle is basically perfect.

I have on occasion lost power well after warm up (once on highway. Once climbing a mountain pass). Both times I pulled over, turned off ignition and everything normalized once started up again. Unfortunately I was not monitoring fuel trims on these two occasions.

Any guesses? Seems like an electrical or sensor issue more than a mechanical one to me...

 

Hey,

No check engine lights or anything correct? I just had mine come on with a p0023 and that apparently can have similar issues.

Stopped at an auto shop and the guy said this is an issue he has seen with some other Tacoma’s lately. But can’t call the dealership and ask since it’s Labor Day.

 

fuel pressure?

 

Open loop or closed loop status?

 

I just put in a new fuel pump and filter... so probably good.

 

Honestly I cant seem to see the status... but the STFT will stay at zero well after engine is warmed up. So I would guess in both open and closed.

Only thing that seems to change it is ignition off/on again.