Throttle response. Dead spot?

[krewat]

So, some history - my 2013 had this annoying thing where if I was in Sport mode, and say, I was taking off aggressively, and had to left off the go-pedal for a second, and then get back on it, it would just go "whatever" and wait for a few seconds. If I didn't move the pedal, it would eventually get the idea "hey, he wants to get up and go" and it would GO like it should.

It's not a hesitation like a carb with no accelerator pump or anything, just this "dumb" spot where it's like it didn't realize it needed to move.

I'm not sure if it was tranny-related, like it was waiting for everything to settle down before it went again, or what.

Guess what? As far as I can tell, my brandy-new 2016 does the SAME THING.

And no, it's not the "oh my god, complete loss of acceleration when trying to take off into heavy traffic" some of the '13's and maybe the 12's had, which was fixed by a calibration update.

This is just a completely "I'm stupid" moment from the PCM.

Is this normal? Does a tune take care of it? It makes playing around a non-starter.

NOTE: If I recall correctly, it does the same thing in normal "D", just not as pronounced.

I'll have to get my act together and document the issue. I brought my '13 to the dealer once for a recall (axle shaft actually was coming out of the tranny) and told them to look at it - of course "could not duplicate issue".

thanks everyone!

 

[mcevok]

2015 here, throttle works as expected, even more aggressive in S mode

 

[krewat]

Oh, it's more aggressive in sport mode, problem is if I left off, and then hit it again, it just goes "duh... what?" for a few seconds.

This is in 2nd or 3rd gear...

 

[Livernois Motorsports]

A tune will remedy SOME of the "brain farts" that the ECM does suffer from. Typically, stock or tuned if you drive conservatively 99% of the time the ECM will stammer for a second. That 1% request of shear aggression will throw the logic for a loop. Having our tune will mitigate that greatly, because we do completely reteach all of the shifting, power creation and power application.

 

[krewat]

My '13 didn't get driven "conservatively", matter of fact it was almost 100% of the time in Sport (tranny) mode

Still looking for more real-world experience from people who know exactly what I'm talking about

 

[Livernois Motorsports]

I know exactly what hesitation you are referencing to. Just because the car is in sport mode doesn't mean that it is driven aggressively. I wanted to accurately address your question regarding the tuning aspects, and its impact on the car's logic.

There are certain bits of logic that are built into the factory and aftermarket tuning that will give you the feeling that the car is unsure of what you are asking for at given times. This is built in for several reasons. Some reasons are to save the car from being put into a situation that the stability systems deem are unsafe. This "fact checking" process will take some time, hence a hesitation.

Nor is the car is actually not more "aggressive" in sport mode either. One of the giant things that you "feel" in sport mode is the disengagement of overdrive. This is what makes the car feel like it is always wanting to go faster. It will hang at a higher RPM level in a chosen gear, and this allows for more power to be created at the press of a pedal.

The car's drive by wire systems will allow for you to have more of what you are asking for. For a high-level example, let's say you are accelerating and asking for 25% throttle. Under normal drive conditions, all safeties on and in drive mode the car might give you a continuously expanding percentage of throttle until it sees 25% as safe. Whereas, in sport mode the percentage given to you initially might be 5% more and the grade at which the increased throttle allowed could be doubled. This is the more "aggressive" feeling you are referring to.

 

[krewat]

yeah, I didn't mean that as a "dig" at you or what you were saying, was just trying to get a consensus from the rest of the forum that I'm not nuts. I am, but not about this.

I always assumed "sport" mode (tranny), in terms of increased throttle response just opened the throttle plate(s) more for any given pedal position. So the fly-by-wire logic works not just in absolutes, but also in terms of trends.

I want my throttle cable back or not. There are many reasons I like fly-by-wire more than a cable, one of which probably has to do with tranny temps.

But I digress.

If I could hear from someone who can definitely say "yeah, that's gone (or even a lot better) with tune 'x'" or not, I'd find that enlightening.

BTW, with all traction-control/stability-control turned off on my '13, it still did it. Haven't had a chance to try all that with the '16 yet. I'm trying to be gentle until the engine internals are a little more "shiny" - LOL

Side note, my '13 would never say "sport mode" by double-clicking the traction-control button, even though it was a PP. The '16 does. Can't wait to play around with that.

 

[Livernois Motorsports]

That is probably more of a topic/question for the performance upgrade section.

 

[SHOnUup4]

I've experienced this before also...only with a very abrupt lift from WOT and an immediate request for more throttle, good amount of throttle too.

My thought is that I'd confused it sort of...as it was calculating what gear to toss me in from the abrupt lift, and when I would request for instant throttle again it would just say no.



Sent from my SM-N920V using Tapatalk

 

[2014 TUX/BL SHO]

Ok, I seem to be experiencing something similar to the OP. I've had my car for about a year (bought used with 30,000 miles, now have 42,000). Two or three times in the last month I hit the accelerator pedal and got nothing. A few seconds later, off she went. Once was when I was stopped in traffic waiting to make a left turn on a side street, when traffic opened up I hit the accelerator pedal and ... nada, zilch, zip. Then a second or two later, the car responded. Another time was when I was driving normally through a low speed curve at about 20 mph and gave it some throttle. Same thing, nothing. Then as I wen through the turn, everything ok again. Otherwise, no problems to report except the usual "some days she feels super quick, others, not so much" (I'm guessing ECU/weather related). Is this the way these cars behave? Seems downright unsafe at times to me ...

 

[krewat]

The "sudden loss of any acceleration" thing was solved with a calibration update on my 2013 w/PP.

It still exhibited a dead-spot, when I would be in a turn, say doing less than 30MPH and let off and hit it again, and nothing for a second or two. Makes "playing" with the car almost impossible.

2016 does the exact same thing.

But that thing when you're stopped dead, slam on the go-pedal and it doesn't do anything? That's fixed with a PCM flash update. Worth a try.

 

[2014 TUX/BL SHO]

Ok buddy, thanks for the quick reply!

Your "30 mph lift" example accurately describes what happened to me, good to know I'm not alone with this. Next oil change, I'll mention the PCM flash to the dealer.

Have a great day.

 

[krewat]

Specifically mention "check calibration for updates" on the work order

Also, have them check for other updates too. There was one for the GPS - the red arrow on the nav system would not really be where I was.