Unstable acceleration pattern

When I press the accelerator the process runs in 3 progressive steps until the engine gets best power, I don't think is normal, Someone knows if there is a campaign fixing this? It's like the gasoline mixture is not properly balanced.

 

We're all hoping a reflash is coming...

Under what kind of throttle? Light, medium, WOT...?
My opinion;
A part of AI(D) is to control flex lockup for efficiency. It also uses driver intent and road condition input in it's shift pattern selection. This is a lot of the shifty feeling people get, especially under light load; not so much, an actual shift.
S- mode cancels out flex lockup in the lower gears under light load, where it's really noticeable. It cancels flex lockup completely during heavy load. It also completely cancels the driver intent and road condition input.
In my opinion it's a programming issue with the torque converter or the converter itself. Hell, the programming might even be destroying the torque converter
Try it out in S-5 mode...

 

Driving habits; they hit the sweet spot.
Under light throttle, I think AI is learning bad habits

 

Something else...
The trans temps being reported in the scangauge thread seem high; 195° average.
2nd gen was 170° average.
Something's happening to get that kind of heat...
Rule of thumb says 20-25° temp drop doubles transmission life.

I had the delay every now and then, until I added 1 1/8 qt and had the memory reset via techstream.
I also settled into a habit of letting high idle subside if cold and am more mindful of my brake and shift operation.
I can't say for sure what did it.

 

Good discussion here. OP post highlights a major part of the problem I think

 

and here i am thinking it was part of the otto atkinson recipe...

curious to see what shows up at my first oil service.

 

Oh yes. I've read the threads, downloaded tons of PDFs, etc; from all over the Toyota community. I just didn't pull the theory out my ass...lol.
I plan on doing a full flush at 10K and 30K, and every 30K thereafter.Thinking about Amsoil or Valvoline Maxlife.

 

This method.
https://www.tacomaworld.com/threads/diy-full-flush-for-automatic-transmission.68462/

 

Phshhh...techstream won't know what fluid I have.
Seriously though, I get what you're saying; I respect that.
There are quite a few ATF WS fluids available today.
If Toyota is the only approved ATF WS, Toyota would have to provide it free at their specified maintenance intervals. Think I get free fluid from Toyota under the Magnuson-Moss Act?

 

Techstream was a joke...sort of.
I believe the onus is on them.
Regardless, that would be a battle worth fighting; to me.
I already have Redline in the differentials, so...
Hell, the way Toyota is, they'd probably deny me on floor mats anyway.

 

Yup. I want get as much of the old fluid possible, out.

 

I'm in a manual and the power band under WOT feels lumpy. Almost like you can feel the transition between the injectors and cam profiles.

In the video you can see the dyno print out that shows what I'm talking about



Another site put it side by side with the 4.0, Green being the 3.5.

 

That chart is nuts!

 

You feel it in the lower revs, once it gets in the upper R's it smooths out a good bit. It feels so odd.

 

What it's showing is a pretty inconsistent torque curve. I honestly don't know what would fix it besides better programming. But its a perfect good engine mechanically, and it makes more power than the last gen. But it's down on torque in the low end by a good 20ft or so across the board until 4,000 RPM. I'm a believer in displacement myself, I wouldn't mind if they kept the displacement and added the technology that's on the 2GR-FKS.

 

Your thinking is in all likelyhood correct. I'm in a M/T too, and I feel the same non-linear power delivery as the OP. Not to say the auto trans isn't contributing to driveability problems.. It surely is for some members.

Frank

 

A lot of stuff going on between Attkinson and AICS...

 

Agreed. It's like a dyslexic vtec.

 

I have been searching for the cause of this or at least others who are experiencing it. Thanks for this information. Driving up slight hills in 6th gear (6 spd manual) you can definitely feel significant surging. It feels almost like a poorly tuned turbocharged car on partial throttle. Not very good for an OEM tune in my opinion, and makes me a bit worried about engine longevity with tuning like that.

Correct me if I am wrong ,but I thought this type of switchover tuning was used in the FR-S, so shouldn't Toyota have significant experience with it?

 

I've noticed the surging but only at slower speeds on my Auto Trans. Like driving through a neighborhood at 25 to 30mph. It almost feels like a lugging tendency. I can't put my finger on it and it is very intermittent. Interesting that others are noticing it as well.