How about a "Driveabilty Enhancemet" TSB for the 2GR-FKS?

First off, I'm relieved that Toyota has finally decided to do something about the auto trans shifting issues in the form of a flash update. I sincerely hope it works as advertised and you all can get back to enjoying your trucks (especially you, Smitty! , no joke).

Now, lets take this a step further and try to correct what I believe to be the root of all evil WRT the "stoned" throttle response on the 2GR-FKS - ETCS-I or "Electronic Throttle Control - Intelligent".
Specifically, from the engine PDF pg 146 "Normal Throttle Control (Non-linear control)":


My beef is with the delay in both throttle valve angle and ignition timing response (on accel AND decel) in order to realize (in part) excellent "comfort" in all operating ranges. That's all well and good but I'd like to counter this enhancement with the following observations (manual transmission):

1. It's difficult to consistently and properly modulate engine speed when starting out on moderate to steep inclines. Tipping your foot into the skinny pedal when the clutch is at it's "catch" point is a soup sandwich at best;

2. Initial "bog" in first gear can be dangerous in certain heavy traffic situations - I'd like my truck to go EXACTLY when I tell it to;

3. Quick rev matching on downshift can be a shitshow- I've found that the 3-2 can be done nicely - if you absolutely STOMP the gas;

4. Upshifts at speed while on the throttle result in.. you guessed it, a momentary "bog" feeling in the engine once you get back into the gas - sometimes. There are complaints about this in other threads; and

5. Super long rev hang at high RPM while driving a "little more aggressively". Not a big deal I know, but super annoying nonetheless.

Ok, sum the hell up.. I get it. I'D LIKE TO SEE A RE-CALIBRATION OF THE ETCS-I IN THE FORM OF A FLASH UPDATE TO MITIGATE THESE ISSUES. I WILL DEPEND ON MY FOOTWORK FOR SMOOTH OPERATION OF MY TACO, TOYOTA.

Note:

Please don't post things like "Learn to drive a M/T". I've owned more than a few, and this is the ONLY one that has acted in this way.



Frank

 

I was under the impression that the ECT mode disabled the "smoothing", or at least that was the speculation.

Sadly we live in an era of electronic nannies catering to the lowest common denominator. I know there are ways to remove what you're describing- I'm pretty sure cars like the Subaru BRZ & WRX, Ford Focus ST, and so on have gotten aftermarket tuners to work their magic on the throttle by wire system.

The sad truth of the matter is that "Tacoma" is pretty low on the list for these performance companies who do ECU magic.

And this is why I have a weekend car that has no TCS, no ABS, no nothing- except power steering.

 

I'm in a M/T therefore not 100% sure, but I believe the ECT PWR mode is about the transmission shift points etc and not so much about throttle input to response delays.

Man, I'd love to have a weekend machine like that!

Frank

 

My only complaint is the 1-2 rev hang is ridiculous at higher RPM. I need to wait WAY too long for the revs to drop from 3-3.5k down to 2k where it wants to be for second. The other option is shift at a lower RPM from first but I can't stand the clunking and jerking from a quick low RPM 1st to 2nd shift. I get it, the gearing is geared towards optimizing offroad situations which is why I'm OK with it. But I'd be happy if I could get rid of the Rev hang. Unfortunately that's just how manuals are now due to EPA standards.

I agree the electronic engine throttle input needs to be looked at. I get some intense bucking sometimes when I'm expecting engine braking in 2nd gear (not anywhere near lugging the engine, it just bucks randomly all of the sudden). Really throws me off in stop and go traffic when it happens.

Other than that, no complaints, I am glad I went manual. I'm 5k miles in and I still have some not so smooth shifts every so often, but it's getting better. This is my first manual though and I'm learning on my own so only time will tell if I'm doing things right.

 

Yeah, the rev hang is a head scratcher for sure. Don't get me wrong, I too am glad I got the manual.. I just don't need the ECM's intevention screwing with my throttle inputs lol. What RPM are you at when the bucking happens?

Frank

 

for those of you experiencing the throttle hang, so far I've noticed that a few things seem to help with it:
1. switch transmission fluid for Redline MT90. I put this first because it might be all you have to do, the stuff is butter for our transmissions
2. learn to let off the gas a quarter to half a second before you're going to let out the clutch, not long enough you lose speed but just long enough for the throttle by wire to catch up with you
3. Shift at higher rpm, but don't floor it once you're past 4-4.5k rpm in first, instead start rolling off the gas right at 4500 slowly enough that its still picking up engine speed and then let off all the way at like 5-5.5k. Sounds counter-intuitive, I know, but try letting the engine build up to high rpm and then go to shift, its helped me quite a bit with the rpm hang issue.

Im not 100% sure on this, but lately I've been thinking it could be something to do with the atkinson cycle programming that gives it that rev hang, i understand the truck switches to the otto cycle at higher rpm and that seems to help alleviate the issue as I said above. Regardless, its long since time that Toyota either tune these glitches out with the TBW system or they get out of the way and let aftermarket companies do it

 

Thanks for the detailed post, I appreciate it. It is quite ironic that we have to come up with all these work arounds to drive smoothly/avoid annoying characteristics of the engine setup.

Frank

 

It really is... I am beginning to get the feeling that Toyota designed this engine with the thinking that a computer would be controlling EVERYTHING about it, and it really doesn't like the 'user input' on shift points I vote toyota opens the door for aftermarket companies to turn these engines back into full otto cycle screamers the way they were meant to be and then we can all have the option to have more drivability and power

 

I have been experimenting with this and I am wondering if it has to do with the way the computer controls timing based on detonation and the traction control. It seems to be better now that I switched to a higher octane gas and turned off traction control (auto led). I am also not positive but I think the steering angle also is an input that is causing me some of the issues.

I had no issues with the traction control in my x-runner but this seems to be far more aggressive.

 

Yeah I've noticed that things tend to be a little smoother with the auto lsd button pushed too. I'll stick with the single biggest upgrade we can do to shift engagement/feel on these trucks outside the URD short shifter (which is a GREAT upgrade) is the redline MT90 tranny fluid. Seriously it changes the whole feel of the shifting on the truck and really smoothed out the transition between gears. I'm thinking a nice heavy weighted knob would be a great upgrade as well, will post back with results

 

hmm, I liked my URD on my second gen. Although, this transmission is way better and I think I may wait to see if the TRD shifter will be made.

 

To each his own! I just didn't want to wait for a much more expensive part that serves the same purpose but that's just me

 

Wow some excellent analysis and discussion here OP!

 

Yes, great post to kick it off. This is my main gripe and something that honestly has put me in danger. I said go and it waited a good 3 seconds before it went. By then I couldn't merge and had to pull over into the oncoming traffic lane! This is a serious safety concern and not just a minor drivability issue.

 

Yes, please do..

 

I have no idea what the emissions/EPA certification implications would be, but it would be great to swap to a simple "linear" throttle control when a sport mode button is depressed.

 

Agreed.

Recently I was trying to turn left across two lanes of busy oncoming traffic into a local business (urban setting, not at lights). We've all been there, done it a hundred times. Clutch out smoothly and on to the gas, but it decided to wait for a couple of seconds before lurching forward. The rpms were fine, it just wouldn't respond to my input. I wouldn't sensationalize it by saying the guys in the other lanes had to slam on their brakes, but my passenger kinda looked at me like -what the hell was going on there? It felt like what would happen in an old school carbureted engine when you hit the gas and the choke is still closed - boooog.

Frank

 

I thought about the flywheel weight too, but I have no idea what Toyota uses on these engines. One thought on this though - and help me out here because you obviously know your stuff... wouldn't a heavy flywheel create a more or less linear effect on engine speed? I mean, this delay I speak of only seems to happen for a short time when you first get into the throttle. After that, the power ramps up sharply. I agree though, a heavy rotating mass could definitely cause RPM hang at high engine speed. Hmmm.. throttle map. You just gave me another idea - I'll have to experiment with throttle response before the engine has warmed up - open loop?

Raising the issue, getting discussion going and complaints logged is my ultimate goal here. I appreciate all feedback, it get's people thinking!

Frank

 

Thanks, that was my intent

Frank

 

Thanks for this, and yes I've disconnected my battery a couple of times - same same. I always run "better" fuel, in other words no ethanol. That seems to quiet down the small hesitations I get under moderate load (ie climbing a slight hill in say, 4th or 5th in the 1200-1800 rpm range).
My truck has had this delay since new, October of last year. It most certainly doesn't mean that something could be wrong with it out of the gate, but I'm also seeing others with similar "symptoms", not just in this thread. I find it more than a coincidence that the 2GR-FKS PDF describes throttle angle/timing "control" that seems to fit perfectly with what my engine is doing.
I think I'm not alone in saying a big HELL YEAH to any scanner data you could provide!



Frank