2NZ FE poor acceleration

[HaavardPYA]

Originally Posted by praivo

Sounds like you're getting back on the throttle too late.

Thanks for the answer. I don`t think so, because it happens when i doing rapid shifts. Same thing happens when I´m driving on low revs and put the pedal down too fast. Maybe running rich then, as you said? :)

[Rednaz]

I have the same problem with my 2NZ but I suspect it may be my fuel pump failing? So I'm doing diagnostics and pump replacement next soon.

[praivo]

Originally Posted by HaavardPYA

Thanks for the answer. I don`t think so, because it happens when i doing rapid shifts. Same thing happens when I´m driving on low revs and put the pedal down too fast. Maybe running rich then, as you said? :)

More like running lean and/or not picking up throttle position changes quickly enough. Usually either a REALLY dirty MAF sensor or a bad upstream O2 sensor. On a Yaris it's more than likely to be the MAF sensor. I had to scrape the dirt off mine with a needle to really get it clean and working again.