Engine RPM "Hiccup"/Hesitation during initial acceleration
 

2021 Edit: This "hiccup" during initial acceleration from gears 1-->2 is a result of the torque converter (automatic vehicle) locking up and waiting for the wheels/drivetrain rotation to match the engine before locking to prevent shock. I do not have the symptoms of the DI seal failures which appear during steady state throttle.



Hey guys, I have a new AT Toyota 86 19', and I'm experiencing an issue under initial acceleration. Car's at ~500 miles and has been filled with nothing but 93 Shell for the past 400 miles (car had 115 miles beforehand.) I've noticed this since the odometer hit above
480 miles, but it might have been happening beforehand.

Essentially when accelerating from a stop, once the engine hits gear 2 or 3 and rises to around 2-3K RPM, there's a moment where the car just hits a deadzone that you can feel and see on the tachometer where the power momentarily hesitates before continuing as normal. This is exacerbated if I accelerate harder but is significantly reduced under normal acceleration (but still noticeable and present except under gentle accelerations).

Downshifting and hitting the same relative RPMs without coming to a complete crawl (7-8mph) before accelerating again does not have this issue.

It's most prevalent when driven in manual mode but it also occurs while driven under automatic mode. It's my daily driver and at times I do drive a little more spiritedly but never above 4K RPM.

From what I've read is that this could be a result of the fuel injectors switching. However, I haven't noted anyone mentioning that the issue is not there when traveling under constant speed and I'm having a hard time pinpointing exactly Because of this, I'm guessing that the reason it occurs only once is because of a weird fluctuation as a result of the direct injectors turning on for the first time during initial acceleration?

Here are some example videos that are most closest to my problem from closest to furthest. All of these videos have a sequential chain of hiccups that look repetitive (and it looks to be gear 3 on their vehicles) but mine is only a single bump.

[ame]https://www.youtube.com/watch?v=3AU035Pvkp0[/ame]

[ame]https://www.youtube.com/watch?v=9uO__NJr0Zk[/ame]

[ame]https://www.youtube.com/watch?v=1wKQJfk9qRg[/ame]


I'm not sure if this is an actual problem or just something to live with as a result of a direct and port injection system. I'm new to car enthusiasm in general but I want to learn and keep up as best as I can, which also means nipping any problems in the bud before it becomes a major issue. Is this something I should take the car back to the dealer to have it checked out or is this just a random flub?

The car does have the infamous torque dip in that range, but that's not normal.

inb4 "use search button":bonk:

very hard to say if anything wrong because OP is never feeling the engine's actual power...he never drives above 4 k rpm (have u fallen asleep perhaps??)...that coupled with driving the AT which compared to the MT definitely feels a little mushier and more sluggish due to the torque converter and longer gearing...


all the example clips show the 86s in D, not in the manual mode like OP states is most common for his issue. what is odd about these videos is why the transmission wouldnt automatically downshift to kick the RPMs up if those folks were actually trying to get up to speed. all 3 show they are all moving at decent city speeds so if they push the throttle hard enough the AT should drop down a couple gears..maybe they were very lightly pressing the throttle (would explain the slow accel) and perhaps since the 86's throttle is quite sensitive & precise maybe ECU got confused... but regardless, this doesnt exactly illustrate what OP is explaining..

either take it to the dealer or a shop with someone who has had seat time in 86s with the AT and see if they notice anything unusual..otherwise post up a video of your gauges while in manual mode and launch the car from a stop as you bring each gear close to the redline. don't worry, doubt you'll hurt your new baby if it is at the proper temps ^^ personally i experienced some delay/sluggish throttle response when i had my AT 86 but it was always when my revs were below 5 K and I always figured it was partly due to the torque converter mechanics...needless to say i don't experience any of those sort of nuances with my MT 86..

OP, your car is new so I doubt it, but it might be DI.

I have a '13 86 AT bought second hand. I noticed the same after getting the car and it always happened between 2.3k-2.5k RPM. Especially noticeable in higher gears like 4th or 5th. I was down on power as well and averaging a 0-60mph in around 12s. Took it a garage and the guy after taking it for spin immediately said its a DI issue. Had all 4 changed and things seem to back to normal. Thread is here just in case if it helps.

The OP only has 500 miles on his NEW car, so, I reckon he is just being cautious with the revs till it gets broken in.- :)


humfrz

Hello OwlDance, welcome to the forum and congratulations on your new purchase - :clap:

I don't have an AT, however, what you are experiencing may be just because the car is new and you are new to the car.

I'd suggest you give your car a few thousand miles to break in and maybe things will smooth out.

Also, this car is light and thin, so you hear and feel every little nudge and jerk. In addition, its not a torque monster, so maybe its just not what you are used to.

After a few more miles and your feeling better about revving it up a bit more, that feeling may go away.

If it doesn't, I suggest you take it back to the dealer and express your concern. Maybe drive another AT while at the dealership for comparison.



humfrz

I have a 15' FRS and its been doing that since day one. In manual mode, 2nd gear climbing to 2k-3k rpm it does a a dip or hesitation and then continues to climb like nothing happened. I have no codes, or issues related to that concern. I wouldn't worry about it honestly. Just enjoy the car! :)

Same with my '17 and my wife's '16. Other than it hesitating in 2nd (which is the torque converter just getting hung up) every gear is perfectly fine. When I'm in manual mode, I just keep the RPMs above 3500. Plus I love the afterfire I get between shifts. I agree with @davidsn_670, just enjoy the car!

Very belated thank you for all the replies! As an update to this, I've decided to just keep using the car as normal for the past couple weeks given that it doesn't seem to be a major issue this far. The car is still fantastic to drive and while the little hiccup is always present, it's almost never an issue once the car's actually moving. Tangent, I'm loving this car a ton and accidentally did my first slide without meaning to (wet road, hitting the accelerator a little too hard around a corner) and it handled so smoothly it was practically second nature to correct it; didn't even flinch and only realized "that just happened" a moment after.

If the hesitation/hiccup issue ever exacerbates I'll update this thread further and head to the dealership.

Not normal, bring to dealership since it's under warranty.

Sent from my SM-G960W using Tapatalk

i m for into dealership too

bring it to dealer.

Yeah, not normal. Take it to the dealer when you can. There's normally a lack of power around that RPM range where the car hesitates and you can only get light acceleration without downshifting but the way it's fluttering isn't right.