bryceis250

when i come down hard on the GAS pedal the car comes to a stop for 1-1.5 seconds bringing me forward in the seat then suddenly violently throws me back. a couple times it caused me to jerk the wheel and almost have an accident. something is not right here. some help?

Aspect

Not trying to troll the thread but... physics? If you slam the brakes the forward momentum of the car is shifted towards the front of the car whilst it's decelerating, hence bringing you forward in the seat, and then throwing you back as the deceleration forces stop your car.

I figure that's not the right explanation for this scenario but I thought I'd cover my bases. Given the soft suspension and bushings of these cars, I can imagine the amount of nose dive it'd get from an emergency stop situation. I'd probably check over your bushings and suspension to make sure everything looks in order. Else if you're looking for less brake dive, try getting stiffer suspension, or trying out the RR Racing/FIGS lower mount control arm bushings as they make a night and day difference in brake dive and the dreaded toe wear.

bryceis250

who said anything about brakes. ok, the gas pedal . i hit the GAS PEDAL. why would i be posting a question about hitting the brakes? thanks for your time

bryceis250

but hey still some good info! thanks

Aspect

Woops LOL! My bad man! I prob read it too fast and focused on the " stopping part" first. Literacy at it's finest rofl.... but I assume what you're experiencing when flooring it is the car taking it's time before it finally downshifts. I find this regularly in normal mode where all I do is commute and it's not expecting the gas to be floored so it doesn't react immediately - have you tried the same driving with power mode? The throttle response in power mode should be better. I don't really encounter this problem much anymore after getting the RR Racing tune which makes the gas pedal way more linear in response

2013FSport

iTrader: (2)

Wonder if the tranny is misbehaving?
Please elaborate on the "....comes to a stop for 1....." part of this.
A transmission fault can violently throw you forward. That said I would think the TCM would detect a failed shift, i.e. unexpected output of this magnitude.

That said is it simply laggy and failing to respond or is the car actually decelerating? Please explain.

Drizell

YAY! An intelligent answer!

bryceis250

thanks for your time. im driivng and i come down on the fuel , but it doesnt feel like a transmission thing, it feel like a fuel or air thing, its a very noticeable, like a vacuum or a void for a second or so before it snaps you back in your seat. i guess i cant really explain it much beyound that. id post a video but i dont know how and last time i tried i posted a question on how to with no response.

BDEBDE

Why such an ***?

Ed Fisher

I'm a little new to the throttle by wire system so please take this input as reasonably uninformed as I've not yet learned the players completely on air/fuel metering, delivery, sensing.

This sounds to me like a throttle plate in the body could be hanging up just a little before snapping full open. Could be dirt? Could be lazy sensor? Could be maladjustment? I'd probably take a look at that throttle body and check for smooth operation throughout the range visually. It's relatively easy and there may be a clue in there to lead you.

Again, I'm not posing as any sort of expert but wanted to offer what I may do in your circumstance. Your description did not at all sound like transmission to me either as your revs aren't climbing while the car stays stationary as it would with slippage, and when your throttle input is, after the delay, recognized the vehicle launches with no transmission problems at all.

Good luck in your search, I agree that can be dangerous, and please keep us abreast of your findings.

Ed in Dallas

MikeFig82

iTrader: (13)

I find it good enough just to push down halfway on the accelerator pedal. No need to hammer the pedal. It's drive by wire it's not like a cable controling the TB. You have to learn to feather the pedal if it makes sense. Find the sweet spot. If you mash is it will bogg down, and jerk before it goes.

Other than that there is a small thrust when doing what is explain above. Just not that viloent as what the OP is stating. I also found it less intrusive when I removed the charcoal emission filter. Though my car was running rich as hell. It's since been put back to stock form.

DixieLex

Do you have a 6 speed manual? Other things, AT problem, carbon in a fuel injector, fuel filter plugged.